Feedback method for repetitive uplink transmission in communication system

ABSTRACT

Feedback methods for repetitive uplink transmissions in a communication system are disclosed. An operation method of a terminal may comprise receiving DL data #1 from a base station through a DL data channel #1; receiving DL data #2 from the base station through a DL data channel #2; and when each of a UL control channel #1 on which an HARQ response #1 for the DL data #1 is to be transmitted and a UL control channel #2 on which an HARQ response #2 for the DL data #2 is to be transmitted overlaps with a UL data channel assigned by the base station, transmitting the HARQ response #1 and the HARQ response #2 to the base station through the UL data channel. Therefore, the performance of the communication system can be improved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/777,951, filed on Jan. 31, 2020, which claims priority to KoreanPatent Applications No. 10-2019-0013709 filed on Feb. 1, 2019, No.10-2019-0037259 filed on Mar. 29, 2019, No. 10-2019-0038350 filed onApr. 2, 2019, No. 10-2019-0042099 filed on Apr. 10, 2019, No.10-2019-0049245 filed on Apr. 26, 2019, No. 10-2019-0052539 filed on May3, 2019, No. 10-2019-0130005 filed on Oct. 18, 2019, No. 10-2019-0142650filed on Nov. 8, 2019, No. 10-2019-0145445 filed on Nov. 13, 2019, No.10-2019-0176957 filed on Dec. 27, 2019, No. 10-2020-0007059 filed onJan. 20, 2020, and No. 10-2020-0011087 filed on Jan. 30, 2020 with theKorean Intellectual Property Office (KIPO), the entire contents of whichare hereby incorporated by reference.

BACKGROUND 1. Technical Field

The present disclosure relates generally to feedback technologies in acommunication system, and more specifically, to techniques fortransmitting hybrid automatic repeat request (HARQ) responses for uplinkrepetitive transmissions.

2. Related Art

The communication system (hereinafter, a new radio (NR) communicationsystem) using a higher frequency band (e.g., a frequency band of 6 GHzor higher) than a frequency band (e.g., a frequency band lower below 6GHz) of the long term evolution (LTE) (or, LTE-A) is being consideredfor processing of soaring wireless data. The NR communication system maysupport not only a frequency band below 6 GHz but also 6 GHz or higherfrequency band, and may support various communication services andscenarios as compared to the LTE communication system. For example,usage scenarios of the NR communication system may include enhancedmobile broadband (eMBB), ultra-reliable low-latency communication(URLLC), massive machine type communication (mMTC), and the like.

Meanwhile, in order to support high reliability requirements in thecommunication system, a low code rate may be maintained. When a low coderate is used and time resources are used in a mapping process ofphysical resources (e.g., resource grid), there may not be physicalresources to which a new codeword generated based on new informationbits is mapped. In this case, time resources may be consumed forphysical resource mapping of the new codeword. This may mean a queuingdelay or a delay in a scheduler. If the information bits whosetransmission is delayed correspond to downlink control information(DCI), the transmission delay of the DCI may be referred to as a DCIblocking.

The transmission of the information bits may be delayed until physicalresources are available. In this case, before all transmission of theexisting codeword is completed, the transmission of the new codeword maynot be performed. In addition, a base station may transmit downlink dataafter performing the mapping operation of downlink physical resources,and receives a hybrid automatic repeat request (HARQ) response (e.g.,acknowledgment (ACK)) that is feedback for the downlink data. The HARQresponse may be transmitted on an uplink control channel, and an uplinkdata channel may be transmitted to the base station after encodingand/or modulation processes.

In case that the terminal operates in a communication system supportinga time division duplex (TDD), the base station may dynamically change aslot format. When the number of uplink symbols that can be transmittedis small, the terminal may maintain a reception quality of the HARQresponse by transmitting the uplink control channel in two or moreslots. In this case, the terminal may repeatedly transmit the HARQresponse.

In order to transmit downlink data satisfying the URLLC requirements tothe terminal located at a cell boundary, the base station may determinewhether or not to feed back the HARQ response to the downlink data. Inthe existing communication system, the base station may determinewhether to retransmit the information bits under assumption that theterminal always feeds back the HARQ response to the downlink data. Inthis case, the HARQ response may be transmitted in consideration of apower situation of the terminal, and the terminal may transmit a smallamount of HARQ response at a high power by using a narrow band.Therefore, the transmission of the HARQ response may be delayed.

In addition, the terminal may not transmit two or more uplink channelsdue to power limitation. Therefore, when a new HARQ response isgenerated, the terminal may transmit the new HARQ response using a newuplink control channel.

SUMMARY

Accordingly, exemplary embodiments of the present disclosure providemethods for transmitting HARQ responses for repetitive uplinktransmissions in a communication system.

According to an exemplary embodiment of the present disclosure, anoperation method of a terminal in a communication system may comprisereceiving downlink (DL) data #1 from a base station through a DL datachannel #1; receiving DL data #2 from the base station through a DL datachannel #2; and when each of an uplink (UL) control channel #1 on whicha hybrid automatic repeat request (HARQ) response #1 for the DL data #1is to be transmitted and a UL control channel #2 on which an HARQresponse #2 for the DL data #2 is to be transmitted overlaps with a ULdata channel assigned by the base station, transmitting the HARQresponse #1 and the HARQ response #2 to the base station through the ULdata channel.

At least one DL data channel among the DL data channel #1 and the DLdata channel #2 may be indicated by a dynamic scheduling scheme, and theremaining DL data channel may be indicated by a semi-persistentscheduling scheme.

When a priority of each of the DL data #1 and the DL data #2 isidentical to a priority of UL data to be transmitted through the UL datachannel, the HARQ response #1 and the HARQ response #2 may bemultiplexed in the UL data channel.

Each of the UL control channel #1 and the UL control channel #2 may beconfigured in units of a sub-slot, and the UL data channel may beconfigured in units of a slot comprising two or more sub-slots.

One HARQ response codebook including the HARQ response #1 and the HARQresponse #2 may be generated, and the one HARQ response codebook may bemultiplexed in the UL data channel.

The one HARQ response codebook may be configured in units of a slotcomprising two or more sub-slots.

Arrangement positions of the HARQ response #1 and the HARQ response #2within the one HARQ response codebook may be determined based on timingsof receiving the DL data #1 and the DL data #2.

Arrangement positions of the HARQ response #1 and the HARQ response #2within the one HARQ response codebook may be determined based on timingsof receiving DL scheduling information #1 of the DL data #1 and DLscheduling information #2 of the DL data #2.

UL scheduling information of the UL data channel may be received afterDL scheduling information #1 of the DL data #1 and DL schedulinginformation #2 of the DL data #2, and a size of the UL data channel maybe configured considering a size of the HARQ response #1 and a size ofthe HARQ response #2.

A size of uplink control information (UCI) including the HARQ response#1 and the HARQ response #2 may be estimated based on UL schedulinginformation of the UL data channel, a puncturing operation or arate-matching operation for the UL data channel may be performed basedon the estimated size of the UCI.

A timing of encoding the HARQ response #1 may be identical to a timingof encoding the HARQ response #2.

The HARQ response #1 may be multiplexed in a radio resource overlappingor adjacent to the UL control channel #1 among radio resources occupiedby the UL data channel, and the HARQ response #2 may be multiplexed in aradio resource overlapping or adjacent to the UL control channel #2among the radio resources occupied by the UL data channel.

When the UL data channel is transmitted based on a frequency hoppingscheme, the HARQ response #1 may be transmitted on the UL data channelof a hop #n, the HARQ response #2 may be transmitted on the UL datachannel of a hop #m, and n and m may be different natural numbers.

When the UL data channel includes a plurality of UL data channelinstances, the HARQ response #1 may be multiplexed in a UL data channelinstance #n, the HARQ response #2 may be multiplexed in a UL datachannel instance #m, and n and m may be different natural numbers.

When the UL control channel #1 overlaps the UL data channel instance #nand a UL data channel instance #n+1, the HARQ response #1 may bemultiplexed in the UL data channel instance #n located first in timeamong the UL data channel instances #n and #n+1, and when the UL controlchannel #2 overlaps the UL data channel instance #m and a UL datachannel instance #m+1, the HARQ response #2 may be multiplexed in the ULdata channel instance #m located first in time among the UL data channelinstances #m and #m+1.

When the DL data channel #2 is located after the DL data channel #1 in atime domain, an interval between a last symbol of the DL data channel #2and a start symbol of the UL data channel may be equal to or larger thanan interval configured by the base station.

According to another exemplary embodiment of the present disclosure, anoperation method of a base station in a communication system maycomprise transmitting downlink (DL) data #1 to a terminal through a DLdata channel #1; transmitting DL data #2 to the terminal through a DLdata channel #2; generating uplink (UL) scheduling information of a ULdata channel in consideration of a size of a hybrid automatic repeatrequest (HARQ) response #1 for the DL data #1 and a size of an HARQresponse #2 for the DL data #2; transmitting the UL schedulinginformation to the terminal; and receiving UL data, the HARQ response#1, and the HARQ response #2 on the UL data channel indicated by the ULscheduling information, wherein each of a UL control channel #1 on whichthe HARQ response #1 is to be transmitted and a UL control channel #2 onwhich the HARQ response #2 is to be transmitted overlaps with the ULdata channel.

When a priority of each of the DL data #1 and the DL data #2 isidentical to a priority of the UL data to be transmitted through the ULdata channel, the HARQ response #1 and the HARQ response #2 may bemultiplexed in the UL data channel.

When the UL data channel is transmitted based on a frequency hoppingscheme, the HARQ response #1 may be transmitted on the UL data channelof a hop #n, the HARQ response #2 may be transmitted on the UL datachannel of a hop #m, and n and m may be different natural numbers.

When the UL data channel includes a plurality of UL data channelinstances, the HARQ response #1 may be multiplexed in a UL data channelinstance #n, the HARQ response #2 may be multiplexed in a UL datachannel instance #m, and n and m may be different natural numbers.

According to the exemplary embodiments of the present disclosure, whenphysical uplink control channels (PUCCHs) overlap in the time domain, aplurality of hybrid automatic repeat request (HARQ) response bitsassociated with the corresponding PUCCHs may be multiplexed in one HARQresponse codebook. In addition, when a PUCCH overlaps with a physicaluplink shared channel (PUSCH) in the time domain, HARQ response bits tobe transmitted on the PUCCH may be multiplexed in the PUSCH. Inaddition, PDSCHs belonging to the same subset may be mapped to onePUCCH, and HARQ responses for the PDSCHs belonging to the same subsetmay be transmitted on a PUCCH mapped to the corresponding subset.Therefore, the HARQ responses can be transmitted efficiently, and theperformance of the communication system can be improved.

BRIEF DESCRIPTION OF DRAWINGS

Exemplary embodiments of the present disclosure will become moreapparent by describing in detail embodiments of the present disclosurewith reference to the accompanying drawings, in which:

FIG. 1 is a conceptual diagram illustrating a first exemplary embodimentof a communication system;

FIG. 2 is a block diagram illustrating a first exemplary embodiment of acommunication node constituting a communication system;

FIG. 3 is a timing diagram illustrating a first exemplary embodiment ofa scheduling method in a communication system;

FIG. 4 is a conceptual diagram illustrating a first exemplary embodimentof an encoding method for generating UCI in a communication system;

FIG. 5 is a conceptual diagram illustrating a second exemplaryembodiment of an encoding method for generating UCI in a communicationsystem;

FIG. 6 is a conceptual diagram illustrating a third exemplary embodimentof an encoding method for generating UCI in a communication system;

FIG. 7 is a timing diagram illustrating a first exemplary embodiment ofa method of transmitting UCI in a communication system;

FIG. 8 is a timing diagram illustrating a second exemplary embodiment ofa method of transmitting UCI in a communication system;

FIG. 9A is a conceptual diagram illustrating a first exemplaryembodiment of UL control channels overlapping in the time domain, FIG.9B is a conceptual diagram illustrating a second exemplary embodiment ofUL control channels overlapping in the time domain, FIG. 9C is aconceptual diagram illustrating a third exemplary embodiment of ULcontrol channels overlapping in the time domain, FIG. 9D is a conceptualdiagram illustrating a fourth exemplary embodiment of UL controlchannels overlapping in the time domain, and FIG. 9E is a conceptualdiagram illustrating a fifth exemplary embodiment of UL control channelsoverlapping in the time domain;

FIG. 10 is a conceptual diagram illustrating a first exemplaryembodiment of a mapping relationship between a DL data channel and an ULcontrol channel in a communication system;

FIG. 11A is a conceptual diagram illustrating a first exemplaryembodiment of a method of configuring a DL data channel in acommunication system, and FIG. 11B is a conceptual diagram illustratinga second exemplary embodiment of a method of configuring a DL datachannel in a communication system;

FIG. 12 is a conceptual diagram illustrating a third exemplaryembodiment of a method of configuring a DL data channel in acommunication system;

FIG. 13 is a conceptual diagram illustrating a first exemplaryembodiment of a set including valid TDRA indexes in a communicationsystem;

FIG. 14 is a conceptual diagram illustrating a first exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 15 is a conceptual diagram illustrating a second exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 16 is a conceptual diagram illustrating a third exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 17 is a conceptual diagram illustrating a fourth exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 18 is a conceptual diagram illustrating a fifth exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 19 is a conceptual diagram illustrating a sixth exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 20 is a conceptual diagram illustrating a seventh exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 21 is a conceptual diagram illustrating an eighth exemplaryembodiment of a sub-slot pattern in a communication system;

FIG. 22 is a conceptual diagram illustrating a first exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 23 is a conceptual diagram illustrating a second exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 24 is a conceptual diagram illustrating a third exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 25 is a conceptual diagram illustrating a fourth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 26 is a conceptual diagram illustrating a fifth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 27 is a conceptual diagram illustrating a sixth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 28 is a conceptual diagram illustrating a seventh exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 29 is a conceptual diagram illustrating an eighth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 30 is a conceptual diagram illustrating a ninth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 31 is a conceptual diagram illustrating a tenth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 32 is a conceptual diagram illustrating an eleventh exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem;

FIG. 33 is a conceptual diagram illustrating a first exemplaryembodiment of a method for configuring a TDRA index in a communicationsystem;

FIG. 34A is a conceptual diagram illustrating a second exemplaryembodiment of a method of configuring a TDRA index in a communicationsystem, FIG. 34B is a conceptual diagram illustrating a third exemplaryembodiment of a method of configuring a TDRA index in a communicationsystem, and FIG. 34C is a conceptual diagram illustrating a fourthexemplary embodiment of a method of configuring a TDRA index in acommunication system; and

FIG. 35A is a conceptual diagram illustrating a first exemplaryembodiment of a method for configuring a DL SPS for supporting DL URLLCtraffic in a communication system, FIG. 35B is a conceptual diagramillustrating a second exemplary embodiment of a method for configuring aDL SPS for supporting DL URLLC traffic in a communication system, andFIG. 35C is a conceptual diagram illustrating a third exemplaryembodiment of a method for configuring a DL SPS for supporting DL URLLCtraffic in a communication system.

It should be understood that the above-referenced drawings are notnecessarily to scale, presenting a somewhat simplified representation ofvarious preferred features illustrative of the basic principles of thedisclosure. The specific design features of the present disclosure,including, for example, specific dimensions, orientations, locations,and shapes, will be determined in part by the particular intendedapplication and use environment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present disclosure are disclosed herein. However,specific structural and functional details disclosed herein are merelyrepresentative for purposes of describing embodiments of the presentdisclosure. Thus, embodiments of the present disclosure may be embodiedin many alternate forms and should not be construed as limited toembodiments of the present disclosure set forth herein.

Accordingly, while the present disclosure is capable of variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and will herein be described indetail. It should be understood, however, that there is no intent tolimit the present disclosure to the particular forms disclosed, but onthe contrary, the present disclosure is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of thepresent disclosure. Like numbers refer to like elements throughout thedescription of the figures.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(i.e., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentdisclosure. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” when usedherein, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this present disclosure belongs.It will be further understood that terms, such as those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in greater detail with reference to the accompanying drawings.In order to facilitate general understanding in describing the presentdisclosure, the same components in the drawings are denoted with thesame reference signs, and repeated description thereof will be omitted.

A communication system to which exemplary embodiments of the presentdisclosure are applied will be described. The communication system towhich the exemplary embodiments according to the present disclosure areapplied is not limited to the following description, and the exemplaryembodiments according to the present disclosure may be applied tovarious communication systems. Here, the communication system may beused in the same sense as a communication network.

FIG. 1 is a conceptual diagram illustrating a first exemplary embodimentof a communication system.

Referring to FIG. 1 , a communication system 100 may comprise aplurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2,130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. The plurality ofcommunication nodes may support 4G communication (e.g., long termevolution (LTE), LTE-advanced (LTE-A)), 5G communication (e.g., newradio (NR)), or the like. The 4G communication may be performed in afrequency band below 6 GHz, and the 5G communication may be performed ina frequency band above 6 GHz as well as the frequency band below 6 GHz.

For example, for the 4G communication and the 5G communication, theplurality of communication nodes may support code division multipleaccess (CDMA) based communication protocol, wideband CDMA (WCDMA) basedcommunication protocol, time division multiple access (TDMA) basedcommunication protocol, frequency division multiple access (FDMA) basedcommunication protocol, orthogonal frequency division multiplexing(OFDM) based communication protocol, filtered OFDM based communicationprotocol, cyclic prefix OFDM (CP-OFDM) based communication protocol,discrete Fourier transform-spread-OFDM (DFT-s-OFDM) based communicationprotocol, orthogonal frequency division multiple access (OFDMA) basedcommunication protocol, single carrier FDMA (SC-FDMA) basedcommunication protocol, non-orthogonal multiple access (NOMA) basedcommunication protocol, generalized frequency division multiplexing(GFDM) based communication protocol, filter band multi-carrier (FBMC)based communication protocol, universal filtered multi-carrier (UFMC)based communication protocol, space division multiple access (SDMA)based communication protocol, or the like.

Also, the communication system 100 may further comprise a core network.When the communication system supports the 4G communication, the corenetwork may include a serving gateway (S-GW), a packet data network(PDN) gateway (P-GW), a mobility management entity (MME), and the like.When the communication system 100 supports the 5G communication, thecore network may include an access and mobility management function(AMF), a user plane function (UPF), a session management function (SMF),and the like.

Meanwhile each of the plurality of communication nodes 110-1, 110-2,110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6constituting the communication system 100 may have the followingstructure.

FIG. 2 is a block diagram illustrating a first exemplary embodiment of acommunication node constituting a communication system.

Referring to FIG. 2 , a communication node 200 may comprise at least oneprocessor 210, a memory 220, and a transceiver 230 connected to thenetwork for performing communications. Also, the communication node 200may further comprise an input interface device 240, an output interfacedevice 250, a storage device 260, and the like. Each component includedin the communication node 200 may communicate with each other asconnected through a bus 270.

However, each component included in the communication node 200 may notbe connected to the common bus 270 but may be connected to the processor210 via an individual interface or a separate bus. For example, theprocessor 210 may be connected to at least one of the memory 220, thetransceiver 230, the input interface device 240, the output interfacedevice 250 and the storage device 260 via a dedicated interface.

The processor 210 may execute a program stored in at least one of thememory 220 and the storage device 260. The processor 210 may refer to acentral processing unit (CPU), a graphics processing unit (GPU), or adedicated processor on which methods in accordance with embodiments ofthe present disclosure are performed. Each of the memory 220 and thestorage device 260 may be constituted by at least one of a volatilestorage medium and a non-volatile storage medium. For example, thememory 220 may comprise at least one of read-only memory (ROM) andrandom access memory (RAM).

Referring again to FIG. 1 , the communication system 100 may comprise aplurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and aplurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Thecommunication system 100 including the base stations 110-1, 110-2,110-3, 120-1, and 120-2 and the terminals 130-1, 130-2, 130-3, 130-4,130-5, and 130-6 may be referred to as an ‘access network’. Each of thefirst base station 110-1, the second base station 110-2, and the thirdbase station 110-3 may form a macro cell, and each of the fourth basestation 120-1 and the fifth base station 120-2 may form a small cell.The fourth base station 120-1, the third terminal 130-3, and the fourthterminal 130-4 may belong to cell coverage of the first base station110-1. Also, the second terminal 130-2, the fourth terminal 130-4, andthe fifth terminal 130-5 may belong to cell coverage of the second basestation 110-2. Also, the fifth base station 120-2, the fourth terminal130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belongto cell coverage of the third base station 110-3. Also, the firstterminal 130-1 may belong to cell coverage of the fourth base station120-1, and the sixth terminal 130-6 may belong to cell coverage of thefifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1,and 120-2 may refer to a Node-B, a evolved Node-B (eNB), a gNB, a basetransceiver station (BTS), a radio base station, a radio transceiver, anaccess point, an access node, or the like. Also, each of the pluralityof terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may refer to auser equipment (UE), a terminal, an access terminal, a mobile terminal,a station, a subscriber station, a mobile station, a portable subscriberstation, a node, a device, or the like.

Meanwhile, each of the plurality of base stations 110-1, 110-2, 110-3,120-1, and 120-2 may operate in the same frequency band or in differentfrequency bands. The plurality of base stations 110-1, 110-2, 110-3,120-1, and 120-2 may be connected to each other via an ideal backhaullink or a non-ideal backhaul link, and exchange information with eachother via the ideal or non-ideal backhaul. Also, each of the pluralityof base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connectedto the core network through the ideal backhaul link or non-idealbackhaul link. Each of the plurality of base stations 110-1, 110-2,110-3, 120-1, and 120-2 may transmit a signal received from the corenetwork to the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5,or 130-6, and transmit a signal received from the corresponding terminal130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

Also, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1,and 120-2 may support a multi-input multi-output (MIMO) transmission(e.g., single-user MIMO (SU-MIMO), multi-user MIMO (MU-MIMO), massiveMIMO, or the like), a coordinated multipoint (CoMP) transmission, acarrier aggregation (CA) transmission, a transmission in unlicensedband, a device-to-device (D2D) communication (or, proximity services(ProSe)), or the like. Here, each of the plurality of terminals 130-1,130-2, 130-3, 130-4, 130-5, and 130-6 may perform operationscorresponding to the operations of the plurality of base stations 110-1,110-2, 110-3, 120-1, and 120-2 (i.e., the operations supported by theplurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2). Forexample, the second base station 110-2 may transmit a signal to thefourth terminal 130-4 in the SU-MIMO manner, and the fourth terminal130-4 may receive the signal from the second base station 110-2 in theSU-MIMO manner. Alternatively, the second base station 110-2 maytransmit a signal to the fourth terminal 130-4 and fifth terminal 130-5in the MU-MIMO manner, and the fourth terminal 130-4 and fifth terminal130-5 may receive the signal from the second base station 110-2 in theMU-MIMO manner.

Each of the first base station 110-1, the second base station 110-2, andthe third base station 110-3 may transmit a signal to the fourthterminal 130-4 in the CoMP transmission manner, and the fourth terminal130-4 may receive the signal from the first base station 110-1, thesecond base station 110-2, and the third base station 110-3 in the CoMPmanner. Also, each of the plurality of base stations 110-1, 110-2,110-3, 120-1, and 120-2 may exchange signals with the correspondingterminals 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 which belongs toits cell coverage in the CA manner. Each of the base stations 110-1,110-2, and 110-3 may control D2D communications between the fourthterminal 130-4 and the fifth terminal 130-5, and thus the fourthterminal 130-4 and the fifth terminal 130-5 may perform the D2Dcommunications under control of the second base station 110-2 and thethird base station 110-3.

Hereinafter, methods for transmitting and receiving HARQ-responses in acommunication system will be described. Even when a method (e.g.,transmission or reception of a signal) to be performed at a firstcommunication node among communication nodes is described, acorresponding second communication node may perform a method (e.g.,reception or transmission of the signal) corresponding to the methodperformed at the first communication node. That is, when an operation ofa terminal is described, a corresponding base station may perform anoperation corresponding to the operation of the terminal. Conversely,when an operation of the base station is described, the correspondingterminal may perform an operation corresponding to the operation of thebase station.

In the following exemplary embodiments, a DL control channel may referto downlink control information (DCI) or a radio resource used fortransmission of the DCI, and a DL data channel may refer to a DL dataunit or a radio resource used for transmission of the DL data unit. A ULcontrol channel may mean uplink control information (UCI) or a radioresource used for transmission of the UCI, and a UL data channel maymean a UL data unit or a radio resource used for transmission of the ULdata unit.

The DL control channel may be a physical downlink control channel(PDCCH), and the DL data channel may be a physical downlink sharedchannel (PDSCH). The UL control channel may be a physical uplink controlchannel (PUCCH), and the UL data channel may be a physical uplink sharedchannel (PUSCH). In addition, in the following exemplary embodiments, abase station may mean a serving base station, and a terminal may mean aterminal connected to the serving base station.

FIG. 3 is a timing diagram illustrating a first exemplary embodiment ofa scheduling method in a communication system.

Referring to FIG. 3 , the base station may transmit DCI on a PDCCH, andmay transmit downlink data to the terminal through a PDSCH scheduled bythe corresponding DCI. The terminal may receive the DCI from the basestation, and may receive downlink data scheduled by the correspondingDCI from the base station. The terminal may transmit an HARQ responsefor the downlink data to the base station. The HARQ response may betransmitted on a PUCCH. In the following exemplary embodiments, the HARQresponse may mean an HARQ acknowledgement (HARQ-ACK). The terminal maytransmit one or more uplink control channels (e.g., PUCCHs). In thiscase, the HARQ response may be repeatedly transmitted.

On the other hand, the terminal may receive a DL control channel (e.g.,DCI) from the base station (e.g., serving base station). The terminalmay receive a DL data channel scheduled by the DL control channel andtransmit UCI including an HARQ response for the DL data channel to thebase station. The UCI may be transmitted on a UL control channel.

The resource of the UL control channel may be indicated by the basestation. For example, the base station may configure a plurality ofresources (e.g., UL control channel candidates) for the UL controlchannel to the terminal using higher layer signaling (e.g., radioresource control (RRC) signaling). In the following exemplaryembodiments, a higher layer signaling operation may be performed usingan RRC message. The base station may indicate to the terminal oneresource (e.g., one UL control channel candidate) for the UL controlchannel using an implicit signaling method or an explicit signalingmethod (e.g., a specific field included in the DCI).

Time resource information of the UL control channel may include an indexof a slot in which the UL control channel is located, an index (e.g., anindex of the first UL symbol) of UL symbols in which the UL controlchannel is located within the slot, and/or the number of UL symbolsoccupied by the UL control channel. Frequency resource information ofthe UL control channel may include an index (e.g., an index of the firstresource block) of resource blocks in which the UL control channel islocated, the number of resource blocks occupied by the UL controlchannel, information indicating whether to perform frequency hopping ofthe UL control channel, generation information of a spreading sequencefor the UL control channel, and/or generation information of a referencesignal for the UL control channel.

Meanwhile, the terminal may transmit channel state information (CSI) tothe base station (e.g., serving base station) using a UL controlchannel. The terminal may feed back the CSI to the base station using asemi-static reporting scheme or a dynamic reporting scheme. The basestation may configure the type of CSI to be fed back and physicalresources (e.g., UL control channel) for the feedback of the CSI to theterminal through higher layer signaling.

Alternatively, the terminal may identify the location of the radioresources to which the DL data channel is allocated from the DL controlchannel and may identify feedback information (e.g., resourceinformation) for the HARQ response to the DL data channel. The terminalmay indirectly identify a service corresponding to the DL data (e.g.,Enhanced Mobile BroadBand (eMBB) service or Ultra Reliable Low LatencyCommunication (URLLC) service) based on a search space in which a DLassignment is detected. Alternatively, the terminal may indirectlyidentify the service (e.g., eMBB service or URLLC service) correspondingto the DL data using a radio network temporary identifier (RNTI) or asequence used for scrambling of the DCI (or DL assignment information).

When the DCI (e.g., a cyclic redundancy check (CRC) of the DCI) isscrambled with a modulation and coding scheme-cell-radio networktemporary identifier (MCS-C-RNTI) or when the DCI is received in asearch space configured by higher layer signaling, the terminal mayassume that the DL data channel indicated by the corresponding DCIincludes a transport block (TB) or a code block group (CBG) for theURLLC service.

The terminal may feed back an HARQ response for the TB or CBG to thebase station. The HARQ response may be transmitted on a UL controlchannel or a UL data channel. The terminal may identify a resource ofthe UL control channel (or UL data channel) used for transmission of theHARQ response based on a field included in the DCI. The base station(e.g., serving base station) may configure sets of resources (e.g., setsof resources of UL control channel candidates) for the UL controlchannel to the terminal using higher layer signaling.

The terminal may select one set of resources for the UL control channelbased on the amount of UL control information (e.g., UCI) included inthe UL control channel among the sets configured by higher layersignaling. In this case, the terminal may select one set of resourcesfor the UL control channel based on a field included in the DCI receivedfrom the base station. In order to feed back the UCI to the base stationin the communication system supporting the URLLC service, the terminalmay process the UCI on a smaller time unit basis than the conventionalcommunication system. In the conventional communication system, the UCImay be processed in units of slots. The terminal may process the UCI inunits of a sub-slot, a mini slot, or a symbol, which is smaller than theslot.

When the UCI is repeatedly transmitted in a proposed method, theterminal may map UCI having a small number of transmissions to a columnhaving a good quality in a codebook generation process.

When the UCI is not repeatedly transmitted, the terminal may generate acodebook using the conventional method. When the UCI is repeatedlytransmitted, the quality (e.g., reception quality) of the UCI may bedifferent because the size of the codebook is changed. The quality ofthe UCI may mean an error rate. The column having a good quality maymean a column having a low error rate in a generator matrix G. Acodeword C may be obtained through the code book or a product (G·u) ofthe information bits u and the generator matrix G.

Considering the i-th codebook, the information bits may be representedby u(i) and the codeword may be represented by (G(i)·u(i)). Since theinformation bits are represented by a column vector, the codeword mayalso be given as a column vector. The product of the matrices may beperformed in a finite field (GF(2)) consisting of 0s and 1s. In thefollowing exemplary embodiments, the UCI may mean HARQ response(s)(e.g., HARQ-ACK), and the following exemplary embodiments may be appliedto a CSI transmission operation. The bits of the information bitsrepresented by scalar values may be represented by a vector, and theinformation bits may be constructed by concatenating the bitsrepresented by the vector.

In the following exemplary embodiment, it is assumed that m(i) (∈0,1) isthe i-th generated UCI, and the UCI is repeatedly transmitted K times.When the terminal transmits the UCI once (i.e., K=1), it may be definedas u(i)=m(i). When the terminal transmits the UCI more than once (i.e.,K≥2), Equation 1 below may be defined.u(i)=[ƒ_(i,K) {m(i),m(i−1), . . . ,m(i−K+1)}]^(T)  [Equation 1]

ƒ_(i,K) may refer to a permutation function of mixing K elements appliedto the i-th codebook. When the UCI are HARQ responses, u(i) may be acolumn vector consisting of K bits. When the terminal does not generatethe UCI, u(i) may be a column vector consisting of K−1 or less bits. Theprobability that the terminal generates the UCI may be the same as theprobability that the base station transmits a DL control channel to theterminal. Considering the feedback for the DL data channel, since thebase station transmits the TB according to an arrival rate, thegeneration probability of the UCI may be the same as the arrival rate ofthe TB.

The permutation function (ƒ_(i,K)) may output inputs in ascending ordescending order. The permutation function (ƒ_(i,K)) may be apermutation function that first arranges the assigned UCI first.Alternatively, in a proposed method, the permutation function (ƒ_(i,K))may be a permutation function that mixes K elements such that the errorrate of the UCI is minimized.

When K=2, the terminal may generate a codebook (or information bits) bymultiplexing the i-th UCI and the (i+1)-th UCI. The i-th informationbits may be [ƒ_(i,2){m(i−1),m(i)}] and the (i+1)-th information bits maybe [ƒ_(i,2){m(i),m(i+1)}]. The codeword may be generated frominformation bits consisting of K bits. According to a proposed method,one UCI may be generated K times.

FIG. 4 is a conceptual diagram illustrating a first exemplary embodimentof an encoding method for generating UCI in a communication system.

Referring to FIG. 4 , new UCI may be generated when the transmission ofthe UL control channel is not completed. Here, K may be 2. In order toapply a block coding operation, m(i) may be transmitted twice. ƒ_(i) maybe expressed as an interleaver or a permutation function that generatesthe codebook. The block interleaving may be optionally performed, and aconcatenation operation may be performed by a concatenator.

FIG. 5 is a conceptual diagram illustrating a second exemplaryembodiment of an encoding method for generating UCI in a communicationsystem.

Referring to FIG. 5 , new UCI may be generated when the transmission ofthe UL control channel is not completed. Here, K may be 4. m(i) may betransmitted four times. The block interleaving may be optionallyperformed, and the concatenation operation may be performed by theconcatenator.

The codeword generated by the terminal may be expressed as a product ofthe generator matrix and the information bits. Therefore, the codewordgenerated by the terminal may be defined as in Equation 2 below.

$\begin{matrix}{{x(i)} = {{\sum\limits_{k = 0}^{K - 1}{g_{i,k}{m\left( {i + k} \right)}}} = {\left( {g_{i,0}g_{i,1}\ldots g_{i,{K - 1}}} \right)\left( {{m(i)}{m\left( {i + 1} \right)}\ldots{m\left( {i + K - 1} \right)}} \right)^{T}}}} & \left\lbrack {{Equation}2} \right\rbrack\end{matrix}$

In Equation 2, ƒ_(i,K) may be a result of selecting a basis of thegenerator matrix. Since the terminal repeatedly transmits the UCI twice(i.e., K=2), the codeword considered by the base station (e.g., servingbase station) may be an augmented matrix rather than a generator matrix.In this case, Equation 3 below may be defined. Equation 3 may indicate arelationship between the information bits including m(i) and thecodeword when K is 2. Equation 3 corresponds to a case where the UCI isgenerated continuously in the terminal, the equation for generating thecodeword when some UCI does not occur may be changed.

$\begin{matrix}{\begin{pmatrix}{x\left( {i - 1} \right)} \\{x(i)}\end{pmatrix} = {\begin{pmatrix}g_{{i - 1},0} & g_{{i - 1},1} & 0 \\0 & g_{i,0} & g_{i,1}\end{pmatrix}\begin{pmatrix}{m\left( {i - 1} \right)} \\{m(i)} \\{m\left( {i + 1} \right)}\end{pmatrix}}} & \left\lbrack {{Equation}3} \right\rbrack\end{matrix}$

The proposed method may be applied to an arbitrary block coding method.Since a Reed Muller code or a polar code may be applied, a new operationof the terminal in the encoding procedure may be minimized. The terminalmay apply the encoding scheme differently according to the size of thecodebook. When the size of the codebook is equal to or greater than 3bits and equal to or less than 11 bits, the terminal may use the ReedMuller code. When the size of the codebook is 12 bits or more, theterminal may use the polar code. In a proposed method, the generationmethod of the codebook may vary depending on the size of the codebook.

When the size of the codebook is 11 bits or less, the basis of thegenerator matrix G may be selected based on a Hamming distance. In thiscase, a (32, 11) generator matrix G corresponding to the Reed Mullercode may be used. The generator matrix G may be defined as shown inTable 1 below.

TABLE 1 i M_(i,0) M_(i,1) M_(i,2) M_(i,3) M_(i,4) M_(i,5) M_(i,6)M_(i,7) M_(i,8) M_(i,9) M_(i,10) 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 00 0 1 1 2 1 0 0 1 0 0 1 0 1 1 1 3 1 0 1 1 0 0 0 0 1 0 1 4 1 1 1 1 0 0 01 0 0 1 5 1 1 0 0 1 0 1 1 1 0 1 6 1 0 1 0 1 0 1 0 1 1 1 7 1 0 0 1 1 0 01 1 0 1 8 1 1 0 1 1 0 0 1 0 1 1 9 1 0 1 1 1 0 1 0 0 1 1 10 1 0 1 0 0 1 11 0 1 1 11 1 1 1 0 0 1 1 0 1 0 1 12 1 0 0 1 0 1 0 1 1 1 1 13 1 1 0 1 0 10 1 0 1 1 14 1 0 0 0 1 1 0 1 0 0 1 15 1 1 0 0 1 1 1 1 0 1 1 16 1 1 1 0 11 1 0 0 1 0 17 1 0 0 1 1 1 0 0 1 0 0 18 1 1 0 1 1 1 1 1 0 0 0 19 1 0 0 00 1 1 0 0 0 0 20 1 0 1 0 0 0 1 0 0 0 1 21 1 1 0 1 0 0 0 0 0 1 1 22 1 0 00 1 0 0 1 1 0 1 23 1 1 1 0 1 0 0 0 1 1 1 24 1 1 1 1 1 0 1 1 1 1 0 25 1 10 0 0 1 1 1 0 0 1 26 1 0 1 1 0 1 0 0 1 1 0 27 1 1 1 1 0 1 0 1 1 1 0 28 10 1 0 1 1 1 0 1 0 0 29 1 0 1 1 1 1 1 1 1 0 0 30 1 1 1 1 1 1 1 1 1 1 1 311 0 0 0 0 0 0 0 0 0 0

By selecting J bases out of 11 bases by the permutation function(ƒ_(i,j)), an abbreviated generator matrix {tilde over (G)}(32, J) maybe generated. J may be 1 or more and K or less. The codeword may be aproduct of the information bits and the abbreviated generator matrix{tilde over (G)}. The base station may indirectly inform the terminal ofthe size (J) of the codebook using a downlink assignment index (DAI) inthe DL control channel. Therefore, J may be the same value in the basestation and the terminal. Alternatively, the terminal may generate acolumn vector having a length of 11 by attaching 0s to the informationbits composed of J bits, and obtain the codeword x by multiplying thegenerated column vector by the generator matrix G.

When selecting bases from the generator matrix in a proposed method, theselected basis may be independent of the index i of the codebook. Inaddition, the selected bases may have time-invariant properties.

That is, the permutation function may be expressed as ƒ_(K) instead ofƒ_(i,K). Since the permutation function does not need to be designedaccording to the index i of the codebook and does not have a generalfunctional relationship between the index i of the codebook and theindex of the UCI, implementation complexity may be reduced. Thepermutation function may be defined separately according to the size Jof the codebook (e.g., the amount of UL control channel). In case whenK=J=2, the codeword may be defined as in Equation 4 below. The proposedmethod may be applied even when K=J=4.

$\begin{matrix}{\begin{pmatrix}{x\left( {i - 1} \right)} \\{x(i)}\end{pmatrix} = {\underset{\overset{\_}{G}}{\underset{︸}{\begin{pmatrix}g_{a} & g_{b} & 0 \\0 & g_{a} & g_{b}\end{pmatrix}}}\begin{pmatrix}{m\left( {i - 1} \right)} \\{m(i)} \\{m\left( {i + 1} \right)}\end{pmatrix}}} & \left\lbrack {{Equation}4} \right\rbrack\end{matrix}$

Equation 4 may represent a relationship between the information bits andthe code word including m(i) when K is 2. Each of a and b may be anatural number equal to or greater than 1 and equal to or less than 11,and may be independent of the index i of the codebook. a and b may bedetermined by f. In order for the base station to decode the codewordincluding m(i), the generator matrix may be interpreted as a newgenerator matrix {tilde over (G)} instead of G or {tilde over (G)}.{tilde over (G)} may affect the error rate of the UL control channel.

When the bases of the generator matrix are selected in a proposedmethod, the same basis may not be selected.

Therefore, each of a and b in Equation 4 may have a different value. Inthe procedure of generating the codeword by the terminal, the ReedMuller code G may be reused as a new generator matrix by properlydefining the permutation function or the codebook generation procedure.Since a is different from b, the terminal may obtain the codeword bymultiplying the information bits by the generator matrix {tilde over(G)}. In order to minimize the error rate of m(i) in the generatormatrix {tilde over (G)}, a column having a good characteristic among thecolumns of G may be selected.

The base station (e.g., serving base station) may decode m(i−1) beforedecoding m(i). The decoding procedure of the base station may start withthe codeword excluding m(i−1). For example, Equation 4 may be modifiedto Equation 5 below. The error rate of m(i) may be determined by Gcorresponding to a partial matrix of G. When K is 2 and m(i−1) is known,Equation 5 may indicate a relationship between the information bits andthe codeword including m(i).

$\begin{matrix}{{\begin{pmatrix}{x^{\prime}\left( {i - 1} \right)} \\{x(i)}\end{pmatrix} = {\begin{pmatrix}0 & g_{b} & 0 \\0 & g_{a} & g_{b}\end{pmatrix}\begin{pmatrix}{m\left( {i - 1} \right)} \\{m(i)} \\{m\left( {i + 1} \right)}\end{pmatrix}}},{\overset{\overset{\_}{\_}}{G}:=\begin{pmatrix}g_{b} & 0 \\g_{a} & g_{b}\end{pmatrix}}} & \left\lbrack {{Equation}5} \right\rbrack\end{matrix}$

In a proposed method, a Hamming distance between the codewords accordingto the generator matrix G may be maximized.

The column vector of G in Equation 5 may be given as ‘[g_(b),g_(a)]^(T),[0,g_(a)]^(T)’, and the Hamming distance between the codewords may bemaximized also when m(i−1),m(i),m(i+1)∈{0,1} is applied. The Hammingdistance may be calculated for each dimension, the terminal may repeatthe UCI transmission twice by selecting two columns with a far Hammingdistance from the Reed Muller matrix (G), and may optimize the case ofthe codebook having the size of 2 (e.g., K=2, J=2).

Examining the column vectors of the Reed Muller matrix, a set consistingof column vectors that maximize the Hamming weight of each column andthe Hamming distance between columns may be obtained. The proposedgenerator matrix may always include a column vector consisting of onlyone, and the other column of the proposed generator matrix may be anarbitrary one column among the second to tenth columns (e.g., the secondto tenth columns of Table 1). In addition, the proposed generator matrixmay not include the eleventh column (e.g., the eleventh column of Table1). Here, the presented order may mean the order of generator matricespresented in the 3GPP technical specification (e.g., NR technicalspecification). In the proposed generator matrix G, a may be 1 and b maybe 2.

When a part of the UCI is insufficient in the terminal, J may be greaterthan or equal to 1 and less than K. In this case, the permutationfunction J may be changed. If m(i+1) is not present, Equation 5 may bemodified to Equation 6 below. When K is 2, Equation 6 may indicate arelationship between the information bits and the codeword includingm(i). Since the base station knows m(i−1), the generator matrix G may besufficient to optimize only [g_(b), g_(a)]^(T). In a proposed method,the column maximizing the Hamming distance may be a column satisfying“a=b=1”.

$\begin{matrix}{\begin{pmatrix}{x\left( {i - 1} \right)} \\{x(i)}\end{pmatrix} = {\underset{\overset{\_}{G}}{\underset{︸}{\begin{pmatrix}g_{a} & g_{b} & 0 \\0 & g_{a} & g_{b}\end{pmatrix}}}\begin{pmatrix}{m\left( {i - 1} \right)} \\{m(i)} \\0\end{pmatrix}}} & \left\lbrack {{Equation}6} \right\rbrack\end{matrix}$

In a proposed method, the first bit transmitted by the permutationfunction ƒ_(J) may correspond to a column vector consisting of only one.The bits transmitted second or later by the permutation function ƒ_(J)may have another column (e.g., one of the second to tenth columns).Also, the bits transmitted second or later by the permutation functionƒ_(J) may not include the eleventh column. Here, the presented order maybe the order of generator matrices presented in the 3GPP specification(e.g., the order of Table 1).

When the proposed method is applied, codewords having a valid generatormatrix G may have a large Hamming distance. The proposed method may beapplied to a case where K is less than or equal to 10, and the terminalmay generate the codeword through a simple multiplication using the ReedMuller generator matrix.

In a proposed method, when the size of the codebook is 12 bits or more,the bases of the generator matrix may be selected based on thereliability.

When the size of the codebook is 12 bits or more, the terminal maygenerate the information bits or the codebook. The terminal may apply aCRC code and may apply the polar code after applying the permutationfunction (e.g., interleaving).

According to the conventional method, the amount of parity bits of theCRC may vary according to the size of the codebook, and the location ofthe parity bits in the polarization procedure may vary. The codewordobtained as a result of the CRC may have a systematic form having theinformation bits and the parity bits. The codeword of the CRC may bemapped to a bit channel having high reliability. The parity bits may befurther generated, and the generated additional parity bits may bemapped to a bit channel having higher reliability than the bit channelto which the previous parity bits are mapped.

The information bits and the parity bits may be concatenated and amatrix G_(N) may be obtained by a Kronecker product of the polar codinggenerator matrices (e.g., base matrices defined in the 3GPPspecification). The codeword may be obtained by multiplying theconcatenation result between the information bits and the parity bits bythe matrix G_(N). The matrix G_(N) obtained by the Kronecker product ofthe polar coding generator matrices may be defined as in Equation 7below.

$\begin{matrix}{G_{N}\left( {= {{\underset{\underset{n{times}}{︸}}{{G_{2} \otimes G_{2} \otimes \ldots \otimes G_{2}},{N = 2^{n}},}G_{2}} = \begin{pmatrix}1 & 0 \\1 & 1\end{pmatrix}}} \right)} & \left\lbrack {{Equation}7} \right\rbrack\end{matrix}$

Thereafter, the codeword may be mapped to radio resources (e.g.,resource elements (REs)) after a rate matching operation is performed. Aproblem of determining the location in the polar encoding procedure maybe interpreted as a problem of designing the permutation function(ƒ_(i,j)) when the size of the codebook or the size of the UCI is J.

The J bases may be selected by the permutation function (ƒ_(i,j)), andeach base may be multiplied to each bit of the UCI. The base station mayindirectly inform the terminal of the size J of the codebook using a DAIin the DL control channel. Therefore, J may be the same value in thebase station and the terminal. The 3GPP specification may define thesize of the polar coding generator matrix in the encoding procedure.Accordingly, the terminal may generate a column vector having a requiredlength by attaching 0s to the information bits composed of J bits, andmay obtain the codeword by multiplying the generator matrix and thegenerated column vector.

In a proposed method, bases having high reliability may be selected fromthe vector multiplied by the polar coding generator matrix, and theselected bases may correspond to UCI having a small number oftransmissions. The 3GPP specification defines the order of reliabilityaccording to the size of the polar coding generator matrix, and theproposed method may be implemented based on the order of reliabilitydefined in the 3GPP specification.

In a proposed method, the basis or bases with a large Hamming distancemay be selected from the vector multiplied to the polar coding generatormatrix, a basis having the highest reliability among two or moreselected bases when the number of selected bases is two or more, and theselected basis may correspond to UCI having a small number oftransmissions. The 3GPP specification defines the order of reliabilitiesaccording to the size of the polar coding generator matrix, and theproposed method may be implemented based on the order of reliabilitiesdefined in the 3GPP specification.

In a proposed method, a codebook may be defined that optimizes a freedistance in the augmented generator matrix.

In the case of generating the codebook in the UCI repetitivetransmission procedure, the UCI having a small number of transmissionsmay be mapped to a column having a good quality. The augmented generatormatrix in Equation 3 may be defined as in Equation 8 below. Therefore,the augmented generator matrix of Equation 8 may be in form of atime-varying linear system, and may greatly affect the error rate of theinformation bits.

$\begin{matrix}\begin{pmatrix}g_{{i - 1},0} & g_{i - {1_{\prime}1}} & 0 \\0 & g_{i,0} & g_{i,1}\end{pmatrix} & \left\lbrack {{Equation}8} \right\rbrack\end{matrix}$

The augmented generator matrix may be generalized to an arbitrary largematrix depending on the size of UCI under consideration. Since the sizeof the generalized augmented generator matrix depends on the size ofUCI, it may be difficult to optimize the generalized augmented generatormatrix. Thus, it may be desirable to give a structure to the augmentedgenerator matrix, and the implementation may be simplified based onthis.

For example, the augmented generator matrix may have time invariantcharacteristics. The augmented generator matrix may have a form Gdefined in Equation 4. G may be expressed as a block Toeplitz formgenerated as [g_(a),g_(b)] and may be interpreted as a convolutionalcode.

FIG. 6 is a conceptual diagram illustrating a third exemplary embodimentof an encoding method for generating UCI in a communication system.

Referring to FIG. 6 , a coding procedure for generating new UCI beforecompletion of transmission of a UL control channel may be performedbased on a convolutional coding scheme. Here, K may be 2. A vector maybe generated according to the UCI, and the terminal may generatecodewords x(i) and x(i−1) by combining the previously transmitted UCIwith the generated vector. In the conventional convolutional codingscheme, a convolutional operation on the codeword may be performed on abit basis. In the proposed convolutional coding scheme, a convolutionaloperation on the codeword may be performed on a vector basis. Aconstraint length of the convolutional code may be equal to the numberof repetitive transmissions of the terminal.

Since the codeword is generated based on the convolutional codingscheme, a codeword having the maximum likelihood may be obtained basedon a Viterbi decoding algorithm, and the error rate of the informationbits is determined based on a free distance of the convolutional code.It may be desirable to obtain a codebook or [g_(a),g_(b)] that maximizesthe free distance. In the conventional UCI encoding method, the ReedMuller code or the polar code may be used according to the size of theUCI or the size of the codebook. In a proposed method, the code (e.g.,Reed Muller code, polar code) may be used regardless of the size of theUCI or the size of the codebook. In the UCI repetitive transmissionprocedure, the size of the UCI may not be large. If the size of the UCIis large, a lot of power may be required for transmission of the ULcontrol channel or the UL data channel for the corresponding UCI.

In a proposed method, a column vector constituting the generator matrixof the Reed Muller code may be used as a basis.

In a proposed method and the above-described proposed method, the errorrate of UCI may be a performance criterion for designing g_(a),g_(b). Anindicator for determining the error rate in a proposed method may be thefree distance, and an indicator for determining the error rate in theabove-described proposed method may be the Hamming distance. Since thecode in a proposed method may have a form of the convolutional coderather than the block code, the proposed method may include a case wherea=b. In the case where a≠b, the convolutional coding operation may beperformed by multiplying the generator matrices of the Reed Muller code.

In a proposed method, the codebook may be generated in consideration ofthe number of repetitive transmissions of the UCI.

The terminal may repeatedly transmit the UCI. In a communication systemsupporting dynamic TDD, the terminal may operate based on an indicationaccording to higher layer signaling or dynamic signaling (e.g., DCI) ofthe base station in order to use periodic UL symbols or in order toimprove a received power of the UL.

In the conventional UCI repetitive transmission procedure, the terminalmay map the codeword to a UL control channel or a UL data channel whilemaintaining the codebook in an existing state. Radio resources for theUL control channel may also be maintained. The base station may receivethe UCI from the terminal, and a new transmission may not be instructedto the terminal before the terminal completes the transmission of the ULcontrol channel or the UL data channel.

The base station may reduce a transmission delay time of DL data or ULdata by minimizing the scheduling constraint. In the transmissionprocedure of the DL data, the base station may increase the size of theTB to quickly obtain the UCI. Since the DL data is transmitted through asmall number of TBs, the number of transmissions of the DL data channelmay be reduced. Thus, indirectly, the size of the UCI (e.g., HARQresponse) may be reduced. If the size of the TB is large and theterminal fails to decode the corresponding TB, the size of the resourceused by the base station for retransmission of the corresponding TB mayincrease. Therefore, increasing the size of TB may not be a good method.

The codebook may consist of UCIs mapped to the same UL control channelor UL data channel. The UCI indicated by the base station may be mappedone-to-one with radio resources of the UL control channel. The mappingrelationship between the UCI and the radio resources of the UL controlchannel may be applied to the UCIs that are repeatedly transmitted. TheUL control channel may be transmitted one or more times in a slot, andthe UL control channel may be transmitted using the same radio resourceor different radio resources. The terminal may repeatedly transmit theUCI as many times as indicated by the base station. Therefore, in aproposed method, the terminal may generate the codebook for all the UCIsmultiplexed in the UL control channel or the UL data channel.

The order of UCIs (e.g., HARQ response bits) belonging to the HARQresponse codebook may be configured in ascending or descending order ofreception timing of the DL control channels or the DL data channels.

The base station may configure the terminal to perform the repetitivetransmission procedure of the HARQ response using higher layersignaling. In order to minimize the scheduling constraint, the basestation may schedule the terminal to transmit a new UL control channeleven while the terminal transmits the UL control channel.

FIG. 7 is a timing diagram illustrating a first exemplary embodiment ofa method of transmitting UCI in a communication system.

Referring to FIG. 7 , the terminal may transmit a new UL control channelA2 before transmission of a UL control channel B1 is completed. Here,the base station may assign two DL control channels, and the terminalmay feed back two UL control channels.

The base station may transmit a DL control channel A to the terminal,and may transmit a DL data channel A (not shown) scheduled by the DLcontrol channel A to the terminal. The terminal may receive the DLcontrol channel A from the base station, and may receive the DL datachannel A from the base station based on scheduling information includedin the DL control channel A. In addition, the base station may transmita DL control channel B to the terminal, and may transmit a DL datachannel B (not shown) scheduled by the DL control channel B to theterminal. The terminal may receive the DL control channel B from thebase station, and may receive the DL data channel B from the basestation based on scheduling information included in the DL controlchannel B. The terminal may receive the DL control channel A before theDL control channel B, and may receive the DL data channel A before theDL data channel B.

The terminal may generate an HARQ response for the DL data channel Ascheduled by the DL control channel A, and determine radio resources ofUL control channels (e.g., UL control channels A1 and A2) used fortransmission of the HARQ response. The terminal may generate an HARQresponse for the DL data channel B scheduled by the DL control channelB, and determine radio resources of the UL control channels (e.g., ULcontrol channels B1 and B2) used for transmission of the HARQ response.

In the conventional method, the base station may not assign the DLcontrol channel B to the terminal. In a proposed method, in order toreduce the transmission delay time of the UCI, the base station mayassign the DL control channel B to the terminal. Since each of the timeresources of the UL control channel A1 and the time resource of the ULcontrol channel B2 does not overlap with a time resource of another ULcontrol channel, the terminal may transmit the UCI using the UL controlchannel A1 and the UL control channel B2. Since the time resource of theUL control channel A2 overlaps with the time resource of the UL controlchannel B1, the terminal may transmit the UCI using a new UL controlchannel C. In the UL control channel C, the UL control channel B1 may bemultiplexed with the UL control channel A2.

The terminal may generate three HARQ response codebooks having differentsizes. The HARQ response codebook for the UL control channel A1 mayinclude HARQ response bits for the DL data channel A scheduled by the DLcontrol channel A. The terminal may identify the size of the HARQresponse codebook based on a DAI included in the DL control channel A.

The terminal may generate a common HARQ response codebook for the ULcontrol channel A1 and the UL control channel B1, and the common HARQresponse codebook may include HARQ response bits for the DL data channelA scheduled by the DL control channel A and HARQ response bits for theDL data channel B scheduled by the DL control channel B. The terminalmay identify the size of the HARQ response codebook for the UL controlchannel C based on a sum of the DAI included in the DL control channel Aand the DAI included in the DL control channel B. The DAI included inthe DL control channel B may indirectly indicate the size of the UCI(e.g., HARQ response codebook) indicated by the DL control channel B.

The UL control channel B2 may include HARQ response bits for the DL datachannel B scheduled by the DL control channel B. The HARQ responsecodebook for the UL control channel B2 may include HARQ response bitsfor the DL data channel B scheduled by the DL control channel B. Theterminal may identify the size of the HARQ response codebook based onthe DAI included in the DL control channel B.

The terminal may regard the codebook as information bits and obtain thecodeword by performing an encoding operation on the information bits.The codeword may be mapped to the UL control channel A1, the UL controlchannel C, and the UL control channel B2. Therefore, the size and/ororder of the information bits of the UL control channel may vary foreach transmission of the UL control channels of the terminal.

The radio resource of the UL control channel may be obtained from thelast DL control channel received by the terminal among the DL controlchannels indicating the UCI belonging to the HARQ response codebook.Thus, the UL control channel A1 may be obtained from the DL controlchannel A. The terminal may select a set of UL control channels based onthe size of the HARQ response codebook indicated by the DL controlchannel A, and may use a field or a resource unit index (e.g., controlchannel element (CCE) index) of the DL control channel A) to determineone radio resource of the UL control channel A1.

The UL control channel C may be obtained from the DL control channel B.The terminal may select a set of UL control channels based on the sizeof the newly derived HARQ response codebook, and use a field or aresource unit index (e.g., CCE index) of the DL control channel B todetermine one radio resource of the UL control channel C. The terminalmay select a set of UL control channels from the size of the HARQresponse codebook indicated by the DL control channel B, and may use afield or a resource unit index (e.g., CCE index) of the DL controlchannel B to determine one radio resource of the UL control channel B2.

When the UCI is transmitted using a spreading code without a codebook,the terminal may transmit the UCI in the order of receiving the DL datachannels.

The base station may assign a DL data channel to the terminaldynamically or semi-statically (or, semi-persistently). The base stationmay configure a reception periodicity of the DL data channel usinghigher layer signaling (e.g., RRC message), and may transmit DCIincluding frequency resource information and time resource information(e.g., information of time resources in a slot) of the DL data channelthrough a DL control channel. The terminal may receive the RRC messageand the DCI (e.g., DL control channel) from the base station, and mayidentify the reception resource of the DL data channel based on the RRCmessage and the DCI. For example, the terminal may derive an offset fromthe slot in which the DL control channel is received to the slot inwhich the DL data channel is to be received, and may derive thereception resource of the DL data channel based on the offset.

The base station may configure a transmission periodicity of the DL datachannel in units of a unit shorter than a slot. For example, the basestation may configure the transmission periodicity of the DL datachannel to two or seven symbols. The terminal may transmit an HARQresponse for the DL data channel received from the base station to thebase station.

In a proposed method, the terminal may transmit the UL control channelaccording to the reception periodicity of the DL data channel. When theDL data channel includes one TB, the terminal may transmit one HARQresponse bit (e.g., HARQ-ACK bit) for one TB to the base station. Theterminal may multiplex an HARQ response bit for the previously receivedDL data channel and an HARQ response bit for the last received DL datachannel in the same UL control channel. The order of HARQ response bitsmultiplexed in the same UL control channel may follow an order ofreceiving the DL data channels or an inverse order to the order ofreceiving the DL data channels. For transmission of one or two UCI bits(e.g., HARQ response bits), the UL control channel may have the sameformat (e.g., format 0 or format 1). Even when the terminal multiplexesthe HARQ response bits in the same UL control channel, there may be nochange in the transmission of the UL control channel.

In addition, an HARQ response bit for another DL data channel (e.g.,dynamically assigned DL data channel) may be multiplexed in the same ULcontrol channel with the HARQ response bit for the semi-statically (or,semi-persistently) assigned DL data channel. That is, the terminal maytransmit the HARQ response bit for another DL data channel and the HARQresponse bit for the semi-statically (or, semi-persistently) assigned DLdata channel through the same UL control channel.

In a proposed method, the UCI (e.g., HARQ response) may be mappedone-to-one to the resource of the UL control channel, and the terminalmay multiplex the UCI according to the mapping relationship between theUCI and the resources of the UL control channel.

The base station may transmit DCI instructing to feed back the UCI tothe terminal through a DL control channel. The UCI may include one ormore of CSI, HARQ response, and scheduling request (SR). The terminalmay transmit one or more UL control channels in one slot, and thisoperation may be configured by the base station.

In the conventional method, the HARQ response codebook (e.g., HARQ-ACKcodebook) may correspond to the UL control channel. In a proposedmethod, the HARQ response may correspond to the UL control channel, andthe terminal may generate the codebook based on a correspondingrelationship between the HARQ response and the UL control channel.

FIG. 8 is a timing diagram illustrating a second exemplary embodiment ofa method of transmitting UCI in a communication system.

Referring to FIG. 8 , the base station may transmit DCI to the terminalthrough a DL control channel. The terminal may receive the DCI from thebase station (S801). The terminal may determine whether to transmit UCIbased on information included in the DCI, and may identify the size ofthe UCI. In addition, the terminal may identify a resource of a ULcontrol channel (e.g., UL control channel A) based on the informationincluded in the DCI (S802). The terminal may identify whether UL controlchannels (e.g., UL control channels A and B) overlap in the time domain(S803). The UL control channel B may be a resource of a UL controlchannel configured before the UL control channel A.

When the UL control channel A overlaps with the UL control channel B inthe time domain, the terminal may multiplex UCI bits, perform aconcatenation operation on the multiplexed UCI bits, and perform thesame encoding operation on the concatenated result. The multiplexingprocedure may be shared between the base station and the terminal, andthe resource of the UL control channel may be indicated by one DLcontrol channel among the DL control channels received by the terminal.

When the UL control channels indicated by the DL control channelsreceived at the terminal overlap in the time domain, the terminal maytransmit the UL control channel based on the last DL control channelamong the received DL control channels. A specific field included in thelast DL control channel may explicitly indicate the UL control channel.Alternatively, the last DL control channel may indicate the UL controlchannel by an implicit signaling scheme (e.g., the smallest value amongresource unit indexes (e.g., CCE indexes) of the DL control channel).

When one UL control channel is indicated or when the UL control channelsdo not overlap in the time domain, the terminal transmit the UCI using aUL control channel (e.g., UL control channel A or B) indicated by thebase station (S804). For example, the terminal may generate two or moreHARQ response codebooks (or two or more CSI codebooks), and may map eachof the two or more HARQ response codebooks (or two or more CSIcodebooks) to the UL control channel. The two or more HARQ responsecodebooks (or two or more CSI codebooks) may be transmitted in one slot.That is, the terminal may transmit a plurality of HARQ responses throughone slot.

When two or more UL control channels (e.g., UL control channels A and B)overlap in the time domain, the terminal may generate a codebook bymultiplexing a plurality of UCIs (S805). The terminal may derive a newresource for the UL control channel, and may transmit the UCI using thenew resource (S806). Here, the terminal may not transmit two or more ULcontrol channels in the same UL symbol due to the limitation of thetransmission power.

FIG. 9A is a conceptual diagram illustrating a first exemplaryembodiment of UL control channels overlapping in the time domain, FIG.9B is a conceptual diagram illustrating a second exemplary embodiment ofUL control channels overlapping in the time domain, FIG. 9C is aconceptual diagram illustrating a third exemplary embodiment of ULcontrol channels overlapping in the time domain, FIG. 9D is a conceptualdiagram illustrating a fourth exemplary embodiment of UL controlchannels overlapping in the time domain, and FIG. 9E is a conceptualdiagram illustrating a fifth exemplary embodiment of UL control channelsoverlapping in the time domain.

Referring to FIGS. 9A to 9E, the UL control channel may consist of oneor two symbols in the time domain. Alternatively, the UL control channelmay consist of three or more symbols in the time domain. In the timedomain, the UL control channel A may overlap with the UL control channelB. In addition, the UL control channel A may overlap with the UL controlchannel B in the frequency domain.

Referring back to FIG. 8 , the terminal may generate a codebook for eachtype of UCI. If the UL control channels partially overlap in the timedomain, the codebook may be applied to the UCI corresponding to each ofthe UL control channels.

When the UL control channels used for transmission of the HARQ responsesoverlap in the time domain, the terminal may generate the codebook afterarranging the HARQ response bits in appropriate locations. Theappropriate locations may be defined in the 3GPP technicalspecification. The locations of the HARQ response bits may be determinedbased on an ascending or descending order of reception timings of the DLdata channels assigned by the DCI. The terminal may select the DL datachannel(s) associated with the HARQ response(s) transmitted in the sameUL symbol among the HARQ responses for the DL data channels, andgenerate the codebook for the selected DL data channel(s). Thisoperation may be configured by the base station.

When UL control channels used for transmission of CSI overlap in thetime domain, the terminal may select a part of the CSI according to thepriority of the CSI, and generate a codebook for the selected CSI. Theterminal may determine the priority of the CSI without additionalsignaling from the base station. For example, the terminal may determinethe priority of the CSI based on the contents defined in the 3GPPtechnical specification.

When the UL control channels used for transmission of the HARQ responseand the CSI overlap in the time domain, the terminal may generate anHARQ response codebook and a CSI codebook, and may concatenate the HARQresponse codebook and the CSI codebook.

The terminal may generate a codebook for each type of UCI, and mayconcatenate the generated codebooks. The terminal may generate acodeword by performing the same channel encoding operation, and may mapthe codeword to a UL control channel or a UL data channel. The number ofHARQ response codebooks (or the number of CSI codebooks) that can begenerated in one slot and/or the number of UL control channels that canbe transmitted in one slot may be limited according to the processingcapability of the terminal. The terminal may inform its processingcapability to the base station through higher layer signaling.Therefore, since the base station knows the processing capability of theterminal, the base station may perform a scheduling operation inconsideration of the processing capability of the terminal. If atransmission procedure scheduled by the base station exceeds theprocessing capability of the terminal, the terminal may not perform adecoding operation on the last DL data channel assigned by the DCI. Inaddition, the terminal may not expect the base station to schedule atransmission procedure exceeding the processing capability of theterminal.

In a proposed method, the terminal may generate a codebook for aspecific type of UCI. If the UL control channels for transmission of SRand CSI overlap (partially) in the time domain, the terminal maygenerate a codebook for the SR and may not generate a codebook for theCSI. When the UL control channels for transmission of the HARQ responseand the CSI overlap (partially) in the time domain, the terminal maygenerate a codebook for the HARQ response and may not generate acodebook for the CSI. The terminal may map the generated codebook to theUL control channel. That is, the terminal may report the SR or HARQresponse excluding the CSI to the base station.

In a proposed method, a PRI may correspond one-to-one with a timeresource of the DL data channel, and the UCI may be multiplexed based ona correspondence relationship between the time resource of the DL datachannel and the PRI. The PRI may mean a resource index of the UL controlchannel.

The terminal may receive a DL data channel scheduled by a DL controlchannel (e.g., DCI), and may feed back an HARQ response for the DL datachannel to the base station. The HARQ response may be transmittedthrough a UL control channel, and the UL control channel may beindicated by the PRI included in the DCI scheduling the corresponding DLdata channel or by the PRI and a resource unit index (e.g., CCE index)of the DL control channel.

Even in a situation in which the terminal does not receive the DLcontrol channel (e.g., discontinuous transmission (DTX)), the number ofUCIs determined by the base station may be the same as the number ofUCIs determined by the terminal. If the number of UCIs determined by thebase station is different from the number of UCIs determined by theterminal, the number of resources of the UL control channel, which isderived by the base station, may be different from the number ofresources of the UL control channel, which is derived by the terminal.In this case, the base station should perform a detection operation ofthe UL control channel in consideration of various situations.Accordingly, the size of the HARQ response codebook may be indicated tothe terminal by higher layer signaling as well as dynamic signaling(e.g., DCI).

Meanwhile, the DCI may include an offset of a slot for feedback of theHARQ response and a resource index (PRI) of the UL control channel. Theresource to which the UL control channel is mapped may be indicated bythe slot offset and the PRI included in the DCI. The terminal may applya time window for generating an HARQ response codebook from the slot fortransmitting the UL control channel. The time window may consist ofslots according to a feedback timing of the HARQ response indicated bythe DCI.

The terminal may generate an HARQ response bit in a preconfigured orderfor each location of DL data channel candidates that can be scheduled inthe slot belonging to the time window. When the DL data channel isactually assigned to the terminal, the terminal may express a decodingresult of the TB for the corresponding DL data channel as an HARQresponse bit. If the DL data channel is not assigned to the terminal,the terminal may generate a NACK for the corresponding DL data channel(e.g., DL data channel candidate). The time window may be configured inunits of slots, and the feedback timing of the HARQ response may beconfigured in units of slots. Since the terminal transmits the ULcontrol channel once in the slot, the DL data channel candidates may bemapped to one UL control channel.

In order to reduce a time from the transmission of the DL controlchannel for scheduling the DL data channel to the reception of the HARQresponse for the DL data channel in the URLLC service, the terminal maytransmit the UL control channel two or more times in the slot.

Since the time window of the terminal is configured in units of slots,the DL data channel candidates may not correspond to one UL controlchannel. The DL data channel candidates may correspond to a plurality ofHARQ response codebooks. Accordingly, when the size of the HARQ responsecodebook is semi-static, the size of the corresponding HARQ responsecodebook may increase, and accordingly, the size of the UL controlchannel may increase. If the base station does not perform a decodingoperation (e.g., soft combining operation) on the UL control channel(s),the increase in the size of the UL control channel may cause thecoverage of the UL control channel to decrease.

In order to solve this problem, a set of time domain resources of the DLdata channel may be configured in a proposed method. The time domainresources of the DL data channel may be indicated by a slot offset K₁and a time domain resource allocation (TDRA) for the HARQ response. Theset of time domain resources of the DL data channel may be a subset ofan entire set of time domain resources of the DL data channel (e.g.,time resources of the DL data channel, which are indicated bypdsch-TimeDomainAllocationList) configured by higher layer signaling. Inthe following exemplary embodiments, “K₁+TDRA” may be referred to asKTDRA. That is, KTDRA may include K₁ and TDRA.

The serving base station may configure a subset of time domain resourcesof the DL data channel to the terminal using higher layer signaling.When the DL data channel is assigned, a subset to which the KTDRA thatthe corresponding DL data channel has belongs may be determined, and thesize of the HARQ response codebook mapped to the UL control channel forthe DCI scheduling the corresponding DL data channel may be determined.

The base station may transmit DCI including the KTDRA and the PRI to theterminal. The terminal may receive the DCI from the base station, andmay identify the KTDRA and the PRI included in the DCI. The terminal mayregard DL data channels belonging to the subset of KTDRA as the DL datachannel candidates, and generate an HARQ response codebook. For example,the terminal may receive DL data through the DL data channels belongingto the subset of KTDRA, and generate an HARQ response codebook includingHARQ responses for the DL data. The HARQ response codebook may be mappedto the UL control channel indicated by the PRI.

In order to configure the subset of DL data channels (e.g., setconsisting of KTDRAs), the base station may configure the DL datachannel(s) having the same or similar symbol as the last symbolbelonging to the DL data channel indicated by the TDRA to belong to thesame subset of KTDRA.

In a proposed method, the base station may configure DL data channel(s)belonging to a subset of KTDRA using higher layer signaling. The ULcontrol channel may not be limited. Since an HARQ response codebook isgenerated for each subset of DL data channel(s), the base station maydetermine a feedback timing of the HARQ response in consideration of theprocessing capability of the terminal when assigning the UL controlchannel.

In a proposed method, PRI may correspond to KTDRA. That is, the subsetconsisting of the resources of the UL control channel may correspondone-to-one with the subset of the time domain resources of the DL datachannel.

The base station may configure a subset for a set having resources ofthe UL control channel as elements, in which case all elements of theresources of the UL control channel may belong to the subset. Inaddition, the base station may configure a subset for a set having thetime domain resources (e.g., KTDRA) of the DL data channel as elements,in which case all elements of the time domain resources of the DL datachannel may belong to the subset.

The serving base station may inform the terminal of the mappingrelationship between the subsets (e.g., the subset to which the KTDRAbelongs and the subset to which the PRI belongs) using higher layersignaling. The terminal may know the mapping relationship between thesubset to which the KTDRA belongs and the subset to which the PRIbelongs through higher layer signaling. When the DCI including the KTDRAand the PRI is received from the base station, the terminal may derive asubset of the KTDRA corresponding to the PRI according to the mappingrelationship configured by higher layer signaling. The derived subset ofKTDRA may be the DL data channel candidates to which the HARQ responsecodebook is applied, and the size of the HARQ response codebook may bedetermined based on the number of elements belonging to the derivedsubset of KTDRA.

Since the coverage of the UL control channel is determined by the sizeof the HARQ response codebook, the base station may configure a subsetby dividing a list of KTDRAs of the DL data channel as evenly aspossible. In addition, the slot offset K₁ for feedback of the HARQresponse may be configured in units of slots. This exemplary embodimentmay be performed as follows. In the following exemplary embodiments, theTDRA may mean the DL data channel candidate and the PRI may mean the ULcontrol channel candidate.

FIG. 10 is a conceptual diagram illustrating a first exemplaryembodiment of a mapping relationship between a DL data channel and an ULcontrol channel in a communication system.

Referring to FIG. 10 , the base station may configure TDRAs for a DLdata channel (e.g., DL data channel candidate) to the terminal usinghigher layer signaling. For example, six TDRAs may be configured withina DL duration of one slot. In addition, the base station may inform theterminal of a slot offset (K₁), a PRI, and the like for feedback of anHARQ response. For example, DCI including K₁ and PRI may be transmittedfrom the base station to the terminal. Nine PRIs may be configuredwithin a UL duration of one slot. In this case, a TDRA subset may beconsidered instead of a KTDRA subset.

The base station may classify the TDRAs into one or more subsets. Forexample, a subset 1 may comprise TDRA1 and TDRA3, a subset 2 maycomprise TDRA2 and TDRA5, and a subset 3 may comprise TDRA4 and TDRA6.The base station may also classify the PRIs into one or more subsets.For example, a subset 1 may comprise PRI1, a subset 2 may comprise PRI2and PRI3, and a subset 3 may comprise PRI4 to PRI8. The subsets of DLdata channel candidates may correspond to the subsets of UL controlchannel candidates. The base station may inform the terminal of themapping relationship between the subsets of DL data channel candidates(e.g., TDRAs) and the subsets of UL control channel candidates (e.g.,PRIs) through a combination of one or more of higher layer signaling,MAC control element (MAC), and DCI.

The terminal may receive the DCI from the base station, and may obtainK₁ and PRI included in the DCI. When the DCI includes PRI2, the terminalmay generate an HARQ response codebook for TDRA2 and TDRA5 correspondingto PRI2. For example, since the HARQ response codebook includes an HARQresponse bit for TDRA2 and an HARQ response bit for TDRA5, the size ofthe HARQ response codebook may be 2 bits. The terminal may map the HARQresponse codebook to a UL control channel. The UL control channel usedfor transmission of the HARQ response codebook may be determined by K₁and PRI2 included in the DCI.

Meanwhile, the slot may be divided into a plurality of sub-slots, andone slot may be configured to correspond to the PRI. The boundary of thesub-slot may be indicated to the terminal by higher layer signaling.Alternatively, the boundary of the sub-slot may be defined in the 3GPPtechnical specification. The DL data channel assigned by the basestation may be located in one or more sub-slots. Therefore, the firstsub-slot or the last sub-slot to which the TDRA of the DL data channelbelongs may be a reference sub-slot. In this case, an HARQ responsecodebook for all DL data channel candidates belonging to the referencesub-slot may be generated. The terminal may transmit the HARQ responsecodebook through the PRI indicated by the DCI within a UL duration afterthe slot offset (or sub-slot offset) indicated by the DCI from the slot(or sub-slot) in which the DL data channel is received.

The terminal may determine the size (e.g., the number of UCIs) of theHARQ response codebook according to the exemplary embodiment shown inFIG. 10 . For example, the terminal may determine the size of the HARQresponse codebook based on the mapping relationship between the subsetof DL data channel candidates and the subset of UL control channelcandidates.

FIG. 11A is a conceptual diagram illustrating a first exemplaryembodiment of a method of configuring a DL data channel in acommunication system, and FIG. 11B is a conceptual diagram illustratinga second exemplary embodiment of a method of configuring a DL datachannel in a communication system.

Referring to FIGS. 11A and 11B, in a scheme A, the size of the HARQresponse codebook may be different for each sub-slot to which the DLdata channel candidate belongs. In a scheme B, the size of the HARQresponse codebook may be the same in the sub-slots to which the DL datachannel candidates belongs. In the scheme A, a subset 1 may compriseTDRA1, a subset 2 may comprise TDRA2 and TDRA3, and a subset 3 maycomprise TDRA4 to TDRA6. In the scheme B, a subset 1 may include TDRA1and TDRA3, a subset 2 may include TDRA2 and TDRA5, and a subset 3 mayinclude TDRA4 and TDRA6.

In the schemes A and B, one K₁ may be used. The terminal may use one K₁indicated by the base station among a plurality of K₁s. The exemplaryembodiment shown in FIG. 11 may also be applied to an exemplaryembodiment using KTDRA. A DL slot may be divided into three sub-slots,and the sub-slot to which the last symbol of the DL data channelcandidate belongs may be determined as the sub-slot to which thecorresponding DL data channel candidate belongs.

In the scheme A, the lengths of the sub-slots may be the same in thetime domain. In the scheme A, TDRA1 (e.g., DL data channel candidatecorresponding to TDRA1) may belong to the sub-slot 1, and TDRA2 andTDRA3 (e.g., DL data channel candidates corresponding to TDRA2 andTDRA3) may belong to the sub-slot 2, and TDRA4 to TDRA6 (e.g., DL datachannel candidates corresponding to TDRA4 to TDRA6) may belong to thesub-slot 3. In this case, the size of HARQ response codebook for thesub-slot 1 may be 1 bit, the size of HARQ response codebook for thesub-slot 2 may be 2 bits, and the size of HARQ response codebook for thesub-slot 3 may be 3 bits. Accordingly, the base station may receive a ULcontrol channel having a different quality for each sub-slot to whichthe DL data channel belongs.

In the scheme B, the lengths of the sub-slots may be different in thetime domain. For example, the lengths of the sub-slots may be configuredsuch that the number of TDRAs belonging to one sub-slot is the same. Inthe scheme B, TDRA1 and TDRA3 (e.g., DL data channel candidatescorresponding to TDRA1 and TDRA3) may belong to the sub-slot 1, andTDRA2 and TDRA5 (e.g., DL data channel candidates corresponding to TDRA2and TDRA5) may belong to the sub-slot 2, and TDRA4 and TDRA6 (e.g., DLdata channel candidates corresponding to TDRA4 and TDRA6) may belong tothe sub-slot 3. Accordingly, the size of the HARQ response codebook maybe 2 bits regardless of the TDRA of the DL data channel candidate.

The exemplary embodiments illustrated in FIGS. 11A and 11B may beapplied when the DCI indicates one K₁. Even when the communicationsystem supporting the URLLC service operates in the FDD scheme or theTDD scheme, a plurality of K₁s need not be configured by frequentlychanging the UL-DL configuration. However, if the DL resource isallocated more than the UL resource when the size of the DL data islarger than the size of the UL data, the set of K₁ may include aplurality of values. The above-described exemplary embodiment (e.g., theextended scheme of the above-described exemplary embodiment) may beapplied to the generation operation of the HARQ response codebook.

The KTDRA may indicate a time domain resource. The KTDRAs may beclassified into a plurality of subsets, each of which may correspond toan HARQ response codebook. When the set of K₁ includes two or morevalues, the DL data channel may be configured as follows.

FIG. 12 is a conceptual diagram illustrating a third exemplaryembodiment of a method of configuring a DL data channel in acommunication system.

Referring to FIG. 12 , a plurality of TDRAs may be configured in DLdurations of slots 1 to 2. The slot 1 may be contiguous with the slot 2.Alternatively, the slot 1 may be discontinuous with the slot 2. K₁ andTDRA included in DCI may indicate a time resource of a DL data channel,and TDRAs (e.g., KTDRAs) may be divided into a plurality of subsets. Theset of K₁ may comprise a first value and a second value. The first valueof the set of K₁ may be applied to the TDRAs included in the slot 1, andthe second value of the set of K₁ may be applied to the TDRAs includedin the slot 2.

The subset 1 may include TDRA5 in the slot 1, TDRA6 in the slot 1, andTDRA1 in the slot 2. The subset 2 may include TDRA2 in the slot 2, TDRA3in the slot 2, and TDRA4 in the slot 2. The base station may configurethe subset(s) to the terminal using higher layer signaling, and maytransmit DCI including K₁ and TDRA to the terminal. The terminal mayidentify the subset indicated by the DCI (e.g., K₁ and TDRA) among thesubset(s) configured by higher layer signaling, and may identify thesize of the HARQ response codebook for the identified subset.Accordingly, the terminal may generate the HARQ response codebook forthe subset.

The base station may configure the subsets of TDRAs (e.g., KTDRAs) suchthat decoding end timings of DL data channels are the same or similar.The mapping relationship between the DL data channel and the UL controlchannel and the correspondence relationship between the DL data channeland the sub-slot may be the same as or similar to those of theabove-described exemplary embodiment.

In a proposed method, in order to semi-statically signal the size of theHARQ response codebook, the slot may be divided into a plurality ofsub-slots. The number of symbols included in the DL sub-slot may bedifferent from the number of symbols included in the UL sub-slot. Thefirst sub-slot or the last sub-slot to which the KTDRA of the DL datachannel belongs may be a reference sub slot, and a time window of theHARQ response codebook may be configured based on the referencesub-slot.

The slot in which the UL control channel is transmitted (or the firstsub-slot or the last sub-slot) may be derived by applying the feedbacktiming of the HARQ response included in the DCI. The feedback timing ofthe HARQ response may be configured in units of slots or sub-slots. Theresource through which the UL control channel is transmitted may beindicated by the PRI included in the DCI.

According to the definition of the sub-slot, the size of the HARQresponse codebook for the DL data channel may be different depending onthe sub-slot to which the DL data channel is allocated and the sub-slotin which the UL control channel is transmitted. When the terminalreceives the DCI, the size of the HARQ response codebook may beidentical (i.e., one type). Alternatively, since the size of the HARQresponse codebook may vary according to the DCI, the reception quality(e.g., error rate) of the UL control channel at the base station may bedifferent. Therefore, it is preferable that the lengths of the sub-slotsare not configured to be equal so that the size of the HARQ responsecodebook is uniform.

In a proposed method, the DL data channel(s) may correspond to a ULsub-slot (e.g., a UL sub-slot indicated by the base station forfeedback), and the UCI may be multiplexed based on a correspondencerelationship between the DL data channel(s) and the UL sub-slot.

The terminal may receive the DL data channel scheduled by the DL controlchannel (e.g., DCI) from the base station, and may feed back an HARQresponse for the DL data channel to the base station through the ULcontrol channel. The UL control channel used for feedback of the HARQresponse may be indicated by the PRI included in the DCI scheduling thecorresponding DL data channel or by the PRI and the resource unit index(e.g., CCE index) of the DL control channel.

In the communication system supporting the URLLC service, a time (e.g.,dl-DataToUL-ACK of the 3GPP specification) for transmitting the DL datachannel and receiving the HARQ response of the DL data channel should beshort. In order to satisfy the requirements of the URLLC service, asignaling operation requiring a fast HARQ response transmission at thebase station may be necessary, and an operation for the terminal totransmit two or more UL control channels in one UL slot may benecessary.

To support these functions, a sub-slot having a length shorter than aslot may be introduced into the communication system. K₁ and/ordl-DataToUL-ACK may be configured in units of sub-slots. A time (e.g.,K₁) required for feedback included in the DCI scheduling the DL datachannel may be configured in units of sub-slots. The base station mayinform the terminal of the boundary of the sub-slot, and the terminalmay identify the sub-slot used for feedback of the HARQ response for theDL data channel based on the boundary of the sub-slot. The PRI or DAIindicated by the DCI may be defined for each sub-slot.

In a proposed method, the base station may inform the terminal of apattern of sub-slots belonging to one UL slot by using higher layersignaling. The number of sub-slots constituting the slot may be the sameor different, and the length of each of the sub-slots may be the same ordifferent. For example, the length of each of the sub-slots may varydepending on the configuration of the base station.

In a proposed method, when the slot includes a DL symbol, a UL symbol,and/or a flexible (FL) symbol, or even when the slot is configured as aDL slot, a UL slot, or an FL slot, the above-described concept of thesub-slot may be applied. The base station may inform the terminal of apattern of a DL sub-slot or a UL sub-slot belonging to one slot. The DLsub-slot may comprise DL symbols or ‘DL symbol(s)+FL symbol(s)’, and thelength of each of the DL sub-slots may be different. The UL sub-slot maybe composed of UL symbols or ‘UL symbol(s)+FL symbol(s)’, and the lengthof each of the UL sub-slots may be different.

Hereinafter, methods of assigning a DL data channel using DCI andtransmitting an HARQ response for the corresponding DL data channelthrough a UL control channel will be described. A slot may be dividedinto a DL (sub)slot for transmitting the DL data channel and a UL(sub)slot for transmitting the UL control channel. The DL sub-slot maybe configured to be distinguished from the UL sub-slot. Alternatively,the sub-slot may be configured without discrimination between DL and UL.

The sub-slots may be classified based on the following methods. The DLsub-slot may mean a sub-slot to which the last symbol of the DL datachannel belongs. The UL sub-slot may mean a sub-slot to which the firstsymbol of the UL control channel belongs. The base station may informthe terminal of the boundary of the sub-slot using higher layersignaling. Alternatively, the base station may inform the terminal ofthe number of sub-slots or a pattern of the sub-slots (e.g., an indexindicating the pattern of the sub-slots) using higher layer signaling.

In a proposed method, the base station may configure a set or a listincluding resources of UL control channels to the terminal using higherlayer signaling. The set or list including the resources of the ULcontrol channels may be configured on a (UL) sub-slot basis.

In a proposed method, the base station may configure resources of ULcontrol channels to the terminal using higher layer signaling regardlessof the (UL) sub-slot and may configure the (UL) sub-slot to the terminalusing higher layer signaling. The terminal may derive the boundary ofthe (UL) sub-slot based on the information obtained through higher layersignaling, and may distinguish the resources of the UL control channelsbased on the boundary of the (UL) sub-slot. Accordingly, the terminalmay configure the set of the UL control channels belonging to the (UL)sub-slot.

The resources of UL control channels belonging to different (UL)sub-slots may be different. For example, the resource of the UL controlchannel belonging to the (UL) sub-slot 1 may be different from theresource of the UL control channel belonging to the (UL) sub-slot 2.Therefore, the DAI included in the DCI may be calculated for each (UL)sub-slot.

The DCI (e.g., for dynamically assigned PDSCH) and/or the RRC message(e.g., for semi-statically assigned PDSCH (i.e., semi-persistentscheduling (SPS) PDSCH)) may indicate a resource of one UL controlchannel used for feedback of an HARQ response. In addition, the terminalmay identify a resource of one UL control channel based on a combinationof a PRI included in the DCI and an index of a CCE (e.g., DL controlchannel element) to which h the corresponding DCI is mapped.

Meanwhile, in the communication system supporting the URLLC service, theresource of the UL control channel may be indicated only by the PRIincluded in the DCI. Alternatively, if the DCI does not include the PRI,the terminal may identify a resource of one UL control channel based onthe index of the CCE to which the DCI is mapped. The resource of the ULcontrol channel may be located in a UL slot or UL sub-slot(s) forfeedback of the HARQ response.

The DCI may include a slot offset or sub-slot offset for feedback of theHARQ response. The (sub)slot offset may indicate a gap between the DL(sub)slot and the UL (sub)slot. For example, the offset included in theDCI may be a gap between the DL slot and the UL slot. Alternatively, theoffset included in the DCI may be a gap between the DL slot and the ULsub-slot. Alternatively, the offset included in the DCI may be a gapbetween the DL sub-slot and the UL sub-slot. Alternatively, the offsetincluded in the DCI may be a gap between the DL sub-slot and the ULslot.

A time interval for multiplexing the HARQ response may be configured inunits of sub-slots. Even when two or more UL control channels do notoverlap in the time domain, if the first symbols of the two or more ULcontrol channels belong to the same UL sub-slot, HARQ responses to betransmitted through the two or more UL control channels may bemultiplexed. Alternatively, when two or more UL control channels overlapin the time domain, the HARQ responses to be transmitted through the twoor more UL control channels may be multiplexed, and when two or more ULcontrol channels do not overlap in the time domain, the HARQ responsesto be transmitted through the two or more UL control channels may not bemultiplexed.

When the size of the HARQ response codebook is semi-staticallyconfigured (e.g., when a codebook type 1 defined in the 3GPP technicalspecification is used), the HARQ response codebook may be generated inunits of sub-slots.

The DCI may include resources of a DL data channel, a slot offset orsub-slot offset (e.g., HARQ response timing) for feedback of an HARQresponse for the DL data channel, and a PRI. The terminal may identify aUL (sub)slot in which the UL control channel is to be transmitted basedon the HARQ response timing, and may identify a resource of the ULcontrol channel based on the PRI. The HARQ response codebook may includeall HARQ response(s) transmitted in the UL (sub)slot indicated by theDCI.

The terminal may encode the HARQ response codebook using the PRIincluded in the last received DCI, and may map a codeword to theresource of the UL control channel. When the UL control channelsindicated by the PRIs included in the respective DCIs do not overlap inthe time domain, the HARQ responses associated with the corresponding ULcontrol channels may be multiplexed in the same HARQ response codebookif the first symbols of the UL control channels belong to the same UL(sub)slot.

When the size of the HARQ response codebook is dynamically indicated(e.g., when a codebook type 2 defined in the 3GPP technicalspecification is used), the HARQ response codebook may be generated inunits of sub-slots.

The DCI may include resources of a DL data channel, a slot offset orsub-slot offset (e.g., HARQ response timing) for feedback of an HARQresponse for the DL data channel, and a PRI. Also, the DCI may includeat least one DAI. The DAI may be classified into a counter DAI and atotal DAI.

The terminal may identify a UL (sub)slot in which the UL control channelis to be transmitted based on the HARQ response timing, and may identifya resource of the UL control channel based on the PRI. The HARQ responsecodebook may include HARQ response(s) for DL data channels indicated bythe DAI among HARQ responses that can be transmitted in the UL (sub)slotindicated by the DCI. The DAI may be defined for each UL (sub)slot.

The terminal may encode the HARQ response codebook using the PRIincluded in the last received DCI, and may map a codeword to theresource of the UL control channel. When the UL control channelsindicated by the PRIs included in the respective DCIs do not overlap inthe time domain, the HARQ responses associated with the corresponding ULcontrol channels may be multiplexed in the same HARQ response codebookif the first symbols of the UL control channels belong to the same UL(sub)slot.

In a proposed method, the base station may inform the terminal of thenumber of valid sets of DL data channel candidates, and the terminal mayderive the valid DL data channel candidates based on the number of validsets.

In a proposed method, the base station may inform the terminal of thenumber of sets of DL data channels belonging to one slot using higherlayer signaling, a MAC CE, and/or a DCI. Some indexes in a TDRA tableconfigured by higher layer signaling may not be valid depending on aslot format. This is because the DL data channel candidate (e.g., TDRA)may include an UL symbol. The invalid TDRA indexes may be excluded fromthe set. The terminal may identify a set(s) of valid TDRA indexes, andthe number of set(s) of valid TDRA indexes may be indicated by higherlayer signaling.

The valid TDRA indexes may have a specific order. The valid TDRA indexesmay be located in the specific order within the set. When the number ofset(s) including the valid TDRA indexes is L, the terminal may classifyM valid TDRA indexes into L sets. Since the valid TDRA index(es)belonging to one set correspond to the same HARQ response codebook, thesize of the HARQ response codebook may be determined based on the numberof elements belonging to the set. Since the number of elements belongingto the set depends on the number of TDRA indexes, the format of theslot, and the number of sets, the size of the HARQ response codebook maybe determined by semi-static signaling.

For example, the set may include └M/L┘ or ┌M/L┐ valid TDRA indexes. Inthis case, the number of the valid TDRA indexes included in the sets maybe even. The M set may include └M/L┘ valid TDRA indexes, and theM−(└M/L┘×L) sets may include ┌M/L┐ valid TDRA indexes. The sets may besorted in ascending or descending order according to the number of validTDRA indexes included in the sets.

When the number of valid TDRA indexes belonging to the set isdetermined, the terminal may configure valid TDRA indexes having thesame or similar characteristics to the same set.

In a proposed method, an arrangement order of the HARQ responses for theDL data channels corresponding to the valid TDRA indexes belonging tothe set may be determined in ascending or descending order according tothe indexes of the first symbols of the corresponding DL data channelsin the HARQ response codebook. For example, the terminal may select a DLdata channel having the earliest last symbol in the time domain amongthe DL data channels corresponding to the valid TDRA indexes belongingto the set, and may sequentially map HARQ response(s) for DL datachannel(s) having a start symbol earlier than the last symbol of theselected DL data channel within the HARQ response codebook.

FIG. 13 is a conceptual diagram illustrating a first exemplaryembodiment of a set including valid TDRA indexes in a communicationsystem.

Referring to FIG. 13 , since resources according to TDRA indexes 4 and 5include UL symbols, TDRA indexes 4 and 5 may not be valid. When L (e.g.,the number of sets) is 3, the first set may include TDRA indexes 1 and0, the second set may include TDRA index 3, and the third set mayinclude TDRA index 2. Alternatively, the first set may include TDRAindex 1, the second set may include TDRA index 0, and the third set mayinclude TDRA indexes 2 and 3.

In a proposed method, the HARQ response for the DL data channel havingthe last symbol preceding in time among the last symbols of the DL datachannels corresponding to the valid TDRA indexes included in the set maybe located first in the HARQ response codebook. For example, if the lastsymbol of a DL data channel n is located earlier than the last symbol ofa DL data channel p in the time domain, the HARQ response for the DLdata channel n may be located earlier than the HARQ response for the DLdata channel p within the HARQ response codebook. n and p may bedifferent natural numbers.

For example, the terminal may select a DL data channel having theearliest last symbol in the time domain among the DL data channelscorresponding to the valid TDRA indexes belonging to the set, and mayconfigure the valid TDRA indexes corresponding to L DL data channelsfrom the last symbol of the selected DL data channel to the same set.When the number of DL data channels having the earliest last symbol istwo or more, a DL data channel having the earliest first symbol in thetime domain among the first symbols of the corresponding DL datachannels may be included in the set.

According to the slot format, TDRA indexes 4 and 5 may not be valid.When L=3, the first set may include TDRA indexes 1 and 0, the second setmay include TDRA index 2, and the third set may include TDRA index 3.Alternatively, the first set may include TDRA index 1, the second setmay include TDRA index 0, and the third set may include TDRA indexes 2and 3.

In the communication system supporting the URLLC service, the DL datachannels may be configured not to overlap in the time domain. In thiscase, some TDRA indexes may not be valid. The invalid TDRA indexes maybe excluded from the classification procedure of DL data channelcandidates. Therefore, the number of sets including valid TDRA indexesmay be reduced.

In a proposed method, the base station may inform the terminal of aBWP(s) for deriving the boundary of the sub-slot.

The number of sub-slots constituting one slot and the number of symbolsincluded in each sub-slot may correspond to a different time durationaccording to the BWP. The time duration may be a time required for theterminal to decode the DL data channel and transmit the UL controlchannel. The length of the sub-slot may be defined by the number ofsymbols, and the sub-slot may be associated with the time duration.

In a proposed method, sub-slots may be defined within a reference BWP.Since an operating state (e.g., active or inactive) of the BWP to whichthe UL control channel belongs may be dynamically changed, a process ofconverting a sub-slot defined in the reference BWP into a sub-slot to bedefined within an active BWP may be performed. The reference BWP forconfiguring the sub-slot may be a BWP having a specific index among BWPsconfigured in the terminal. For example, a BWP with an index 0 may beconsidered as the reference BWP. The base station may inform theterminal only of sub-slots associated with one BWP. The configuration ofsub-slots associated with one BWP may be applied to all BWPs. Therefore,the amount of signaling of configuration information of the sub-slotsassociated with the BWP may be reduced.

In a proposed method, sub-slots may be defined within all BWPs. The basestation may configure a plurality of BWPs in a carrier to the terminal,and may independently configure the boundary of the sub-slot in each ofthe plurality of BWPs. In this case, the boundary of the sub-slot may beflexibly indicated in all BWPs.

In a proposed method, a pattern of the sub-slot (e.g., the number ofsymbols included in the sub-slot) may be configured uniformly. In thiscase, the pattern of the sub-slot may be configured as follows.

FIG. 14 is a conceptual diagram illustrating a first exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 14 , one slot may include 14 symbols, and one slot maybe divided into four sub-slots. Each of the sub-slots 0 and 2 mayinclude three symbols, and each of the sub-slots 1 and 3 may includefour symbols. The base station may inform the terminal of DL datachannel candidates (e.g., TDRAs) using higher layer signaling. Thenumber of the DL data channel candidates configured by higher layersignaling may be 9, and the base station may transmit DCI including aTDRA index indicating one DL data channel candidate among the 9 DL datachannel candidates.

A sub-slot to which the last symbol of the DL data channel candidatebelongs may be a sub-slot to which the corresponding DL data channelcandidate belongs. In this case, a DL data channel candidate belongingto the sub-slot 0 may not exist. The sub-slot 1 may include TDRA indexes0 and 4, the sub-slot 2 may include TDRA indexes 1, 5, and 6, and thesub-slot 3 may include TDRA indexes 2, 3, 7, and 8. When a sub-slotpattern is defined without distribution of TDRA indexes, the sizes ofsets of TDRA indexes may not be uniform. That is, since the number ofbits of the UCI transmitted through the UL control channel is notuniform, a reception quality of the UCI may be different at the basestation. Therefore, it is preferable to configure the boundary of thesub-slot in consideration of the distribution of the TDRA indexes.Alternatively, it is preferable to directly configure DL data channelsas a set.

FIG. 15 is a conceptual diagram illustrating a second exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 15 , sub-slot patterns may be configured not to beuniform. One slot may include 14 symbols, and one slot may be dividedinto three sub-slots. The number of TDRA indexes included in each of thesub-slots may be the same. The sub-slot 0 may include TDRA indexes 0, 4,and 5, the sub-slot 1 may include TDRA indexes 1, 6, and 7, and thesub-slot 2 may include TDRA indexes 2, 3, and 8. In this case, each ofthe sub-slots may include three TDRA indexes.

The HARQ responses for the DL data channels belonging to the samesub-slot may be mapped to the same UL control channel. For example, thebase station may inform the terminal of L (e.g., the number of sets) andTDRA indexes (e.g., DL data channel candidates) using higher layersignaling. The base station may configure the number of TDRA indexes(e.g., the number of DL data channel candidates) to be a multiple of L.The terminal may divide a slot into L sub-slots, and configureboundaries of the sub-slots such that the number of TDRA indexesincluded in each of the L sub-slots is the same. The boundaries of thesub-slots may not be uniquely divided, but the sets including the TDRAindexes may be uniquely determined.

The base station may inform the terminal of the non-uniform sub-slotpatterns using higher layer signaling. The sub-slot may be composed ofconsecutive symbols, and one slot may be divided into two or moresub-slots. The lengths of the sub-slots may be configured to be the sameor different. In the following, a method for configuring the boundariesof the L sub-slots when the number of (FL symbols+UL symbols) includedin the slot is N or when the number of (FL symbols+DL symbols) includedin the slot is N will be described.

In a proposed method, the numbers of symbols included in the remainingsub-slots except the first sub-slot in one slot may be the same. Thenumber of symbols included in the first sub-slot may be greater than thenumbers of symbols included in the other sub-slots. For example, asub-slot n may include └N/L┘ symbols. Here, n may be a natural number of2 or more and L or less. The sub-slot 1 may include N−(L−1)×└N/L┘symbols. A case where N=14 and L=4 may correspond to an index 5 ofTables 2 and 3.

In Table 2, a sub-slot pattern may be defined based on a start symbol ofthe sub-slot, and in Table 3, a sub-slot pattern may be defined based onthe number of symbols included in the sub-slot. In Table 2, S₁ mayindicate a start symbol index of the sub-slot 1, S₂ may indicate a startsymbol index of the sub-slot 2, S₃ may indicate a start symbol index ofthe sub-slot 3, and S₄ may indicate a start symbol index of the sub-slot4. In Table 3, L₁ may indicate the number of symbols included insub-slot 1, L₂ may indicate the number of symbols included in thesub-slot 2, L₃ indicates the number of symbols included in the sub-slot3, and L₄ may indicate the number of symbols included in the sub-slot 4.

TABLE 2 Number Index (L) S₁ S₂ S₃ S₄ . . . 1 2 0 7 N/A N/A N/A 2 4 0 3 611 N/A 3 4 0 4 8 11 N/A 4 4 0 3 7 10 N/A 5 4 0 5 8 11 N/A 6 4 0 4 7 11N/A 7 7 0 2 4 6 . . . . . . . . . . . . . . . . . . . . . . . .

TABLE 3 Number Index (L) L₁ L₂ L₃ L₄ . . . 1 2 7 7 N/A N/A N/A 2 4 3 3 44 N/A 3 4 4 4 3 3 N/A 4 4 3 4 3 4 N/A 5 4 5 3 3 3 N/A 6 4 4 3 4 3 N/A 77 2 2 2 2 . . . . . . . . . . . . . . . . . . . . . . . .

In a proposed method, the numbers of symbols included in the remainingsub-slots except the last sub-slot in one slot may be the same. Thenumber of symbols included in the last sub-slot may be greater than thenumber of symbols included in the other sub-slot. For example, asub-slot n may include └N/L┘ symbols. Here, n may be a natural numberequal to or greater than 1 and equal to or less than L−1. A sub-slot Lmay include N−(L−1)×└N/L┘ symbols.

In a proposed method, the above exemplary embodiment may be applied whena half slot (e.g., a half of a slot) is used.

The numbers of symbols included in the two sub-slots among the sub-slotsmay be greater than the numbers of symbols included in the remainingsub-slots. In this case, the sub-slots may be the last sub-slot in thefirst half slot and the last sub-slot in the second half slot. Thisexemplary embodiment may be well applied when the number L of sub-slotsis even. For example, to divide N into L sub-slots (e.g., evensub-slots), a sub-slot n may include └N/L┘ symbols. Here, n may be oneof 2, . . . , L/2−2, L/2+1, . . . , and L−1.

A sum of the number of symbols included in the sub-slot L/2 and thenumber of symbols included in the sub-slot L may be N−(L−2)×└N/L┘. Thenumber of symbols included in the sub-slot L/2 may be the same as thenumber of symbols included in the sub-slot L. Alternatively, the numberof symbols included in the sub-slot L/2 may be different from the numberof symbols included in the sub slot L. When N=14 and L=4, the index 4 ofTables 2 and 3 may correspond to a case where the number of symbolsincluded in the sub-slot L/2 is the same as the number of symbolsincluded in the sub-slot L.

In a proposed method, some sub-slots may include the same number ofsymbols, other sub-slots may include the same number of symbols, and adifference between the number of symbols included in each of the somesub-slots and the number of symbols included in each of the othersub-slots may be 1. The number of symbols included in M sub-slots in oneslot may be └N/L┘ and the number of symbols included in each of theremaining L−M sub-slots may be (N−M×└N/L┘)/(L−M). When N=14 and L=4, ifthe index 2 or 3 of Tables 2 and 3 are used, each of the sub-slots 1 and2 may include three symbols, and each of the sub-slots 3 and 4 mayinclude four symbols.

Meanwhile, a method for feeding back an HARQ response withoutconfiguring sub-slots may be used. In a proposed method, DL data channelcandidates may be configured as a set without configuring sub-slots. Forexample, the TDRA indexes shown in FIG. 14 or 15 may be divided into Lsets. The base station may inform the terminal of L sets including theTDRA indexes using higher layer signaling.

For example, the base station may configure TDRA indexes 0, 4, and 5 toa set 1, configure TDRA indexes 1, 6, and 7 to a set 2, and configureTDRA indexes 2, 3, and 8 to a set 3. The base station may inform theterminal of configuration information of the sets 1 to 3 (e.g., the TDRAindex included in each of the sets) using higher layer signaling.

This scheme may be interpreted as configuring a TDRA sub-table from theTDRA table including the TDRA indexes. The terminal may multiplex HARQresponses for TDRA indexes (e.g., DL data channel candidates) belongingto the same set in the same HARQ response codebook, perform an encodingoperation on the HARQ response codebook, and map a codeword to the ULcontrol channel.

In a proposed method, a different boundary of sub-slot may be derivedaccording to a slot format.

In a proposed method, all symbols (e.g., 14 symbols) included in theslot may be configured as sub-slots. When the sub-slot is configuredregardless of the format of the slot, the signaling operation forinforming the pattern of the sub-slot may be simply performed.

For example, in the communication system supporting the FDD scheme,since no DL symbol exists in a slot in which a UL channel istransmitted, all symbols included in the slot may be configured assub-slots. In the communication system supporting the TDD scheme, allsymbols included in the slot may be configured as sub-slots. Among thesymbols included in the slot, FL symbols and UL symbols other than DLsymbols may be configured as sub-slots. Alternatively, all symbolsincluded in a slot in which a DL channel is transmitted may beconfigured as sub-slots. Alternatively, FL symbols and DL symbols otherthan UL symbols among the symbols included in the slot may be configuredas sub-slots. The FL symbols may mean all FL symbols belonging to theslot. Alternatively, the FL symbols may mean some FL symbols amongsuccessive FL symbols.

In a proposed method, some symbols (e.g., less than 14 symbols) includedin the slot may be configured as sub-slots. This exemplary embodimentmay be applied to the communication system supporting the TDD scheme.The base station may inform the terminal of a slot pattern using acombination of one or more among higher layer signaling, MAC CE, andDCI. The boundary of the sub-slot may be determined by higher layersignaling. The terminal may determine the symbols included in thesub-slots based on the slot pattern configured by higher layersignaling. The DL symbol(s) included in the slot in which the UL channelis transmitted may not be configured as sub-slots. In this case, lessthan 14 symbols may be configured as sub-slots. In addition, the ULsymbol(s) included in the slot in which the DL channel is transmittedmay not be configured as sub-slots. In this case, less than 14 symbolsmay be configured as sub-slots. The base station may inform the terminalof the number of sub-slots (e.g., L) by using higher layer signaling. Inthis case, the terminal may classify (FL symbols+UL symbols) or (DLsymbols+FL symbols) included in the slot into L sub-slots.

In a proposed method, the FL symbol may belong to a DL sub-slot or a ULsub-slot.

When the slot includes DL symbol, FL symbol, and UL symbol, a method ofconfiguring a DL sub-slot with only DL symbols may be considered todetermine a sub-slot pattern. When a DL data channel is assigned by DCI,FL symbols may be configured as a DL sub-slot. When a DL data channel(e.g. SPS PDSCH) is assigned by an RRC message, FL symbols may not beused as a DL sub-slot. When an HARQ response for the DL data channelassigned by the DCI and an HARQ response for the DL data channelassigned by the RRC message are multiplexed in the same HARQ responsecodebook, the DL sub-slot may be preferably composed of DL symbols andFL symbols.

FIG. 16 is a conceptual diagram illustrating a third exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 16 , a slot may include eight DL symbols, four FLsymbols, and two UL symbols. A DL sub-slot may be composed of DL symbolsand FL symbols. A TDRA index may mean a DL data channel candidate. ATDRA table used in the exemplary embodiment shown in FIG. 16 may be thesame as the TDRA tables used in the exemplary embodiments shown in FIG.14 or FIG. 15 .

A DL data channel may be assigned to the terminal using TDRA indexes 0,1, 4, 5, 6, and/or 7. A TDRA index corresponding to the DL sub-slot 0may not exist, the DL sub-slot 1 may include TDRA indexes 0, 4, and 5,and the DL sub-slot 2 may include TDRA indexes 1, 6, and 7. When an HARQresponse codebook with a semi-static size is used, three HARQ responsesmay be generated if the DL data channel belongs to the DL sub-slot 1,and three HARQ responses may be generated if the DL data channel belongsto the DL sub-slot 2.

In the communication system supporting the TDD scheme, a DL duration anda UL duration may be divided by FL symbol(s). There may be an FL symbolto which data is not allocated in consideration of a delay arrival time.In this case, since the base station should not assign the DL datachannel having the corresponding FL symbol to the terminal, the DL datachannel having the semi-static size may be configured without thecorresponding FL symbol.

In a proposed method, the serving base station may inform the terminalof the type of the FL symbol using higher layer signaling. An FL symbolhaving a type A may be included in a DL sub-slot, and an FL symbolhaving a type B (e.g., FL symbol to which no data is allocated) may notbe included in a DL sub-slot. In the time domain, the FL symbol havingtype A may be contiguous with the FL symbol having type B. In this case,the types of FL symbols located before a specific timing may bedifferent from the types of FL symbols located after the specifictiming, and the FL symbols located before the specific timing may bedistinguished from the FL symbols located after the specific timing. TheFL symbols having type B located before or after the specific timing maynot be included in the DL sub-slot. The FL symbols having type B may beconfigured as a guard period or a UL transmission period.

FIG. 17 is a conceptual diagram illustrating a fourth exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 17 , a slot may include eight DL symbols, four FLsymbols, and two UL symbols. Two consecutive FL symbols located afterthe DL symbols may be FL symbols having type A, and two consecutive FLsymbols located before the UL symbols may be FL symbols having type B.Ten symbols included in the slot (e.g., eight DL symbols and two FLsymbols) may be used to configure three DL sub-slots. Each of the DLsub-slots 0 and 1 may include three symbols, and the DL sub-slot 2 mayinclude four symbols.

The TDRA index corresponding to the DL sub-slot 0 may not exist, the DLsub-slot 1 may include TDRA indexes 0 and 4, and the DL sub-slot 2 mayinclude TDRA indexes 1, 5, and 6. When the patterns of DL sub-slots areconfigured differently (e.g., when the DL sub-slot 0 is not configured),two DL sub-slots may be configured, one DL sub-slot may correspond totwo TDRA indexes, and the remaining DL sub-slot may correspond to threeTDRA indexes.

In a proposed method, FL symbol(s) may belong to both a DL sub-slot anda UL sub-slot.

The FL symbol(s) belonging to the slot may be included in only a DLsub-slot, only a UL sub-slot, or both the DL and UL sub-slots. A DL datachannel and a UL control channel assigned by DCI may be transmittedthrough the FL symbols. When the size of an HARQ response codebook isdetermined by an RRC message, one or more FL symbols may be included ina DL sub-slot and/or a UL sub-slot.

When one or more FL symbols are included in only a DL sub-slot or only aUL sub-slot, the base station may inform the terminal of configuringinformation of FL symbols constituting the DL sub-slot (e.g., an indexof an FL symbol located at a boundary of the DL sub-slot, an index of anFL symbol that is not included in the DL sub-slot) and/or configurationinformation of FL symbols constituting the UL sub-slot (e.g., an indexof an FL symbol located at a boundary of the UL sub-slot, an index of anFL symbol that is not included in the UL sub-slot).

FIG. 18 is a conceptual diagram illustrating a fifth exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 18 , a slot may include eight DL symbols, four FLsymbols, and two UL symbols. Four FL symbols may be included in a DLsub-slot and a UL sub-slot. Twelve or fewer symbols may be used toconfigure DL sub-slots.

When a DL sub-slot pattern 1 is used, the DL sub-slot 0 may include foursymbols, the DL sub-slot 1 may include four symbols, and the DL sub-slot2 may include four symbols. When a DL sub-slot pattern 2 is used, the DLsub-slot 0 may include six symbols, the DL sub-slot 1 may include foursymbols, and the DL sub-slot 2 may include two symbols. When a DLsub-slot pattern 3 is used, the DL sub-slot 0 may include eight symbolsand the DL sub-slot 1 may include four symbols.

A DL data channel candidate corresponding to TDRA index 7 may not beallocated to secure a UL-DL switching time in a slot n. The DL datachannel candidate corresponding to TDRA index 7 may be considered whenconfiguring a DL sub-slot pattern. Six or fewer symbols may be used toconfigure a UL sub-slot. The UL sub-slot 0 may include three symbols,and the UL sub-slot 1 may include three symbols.

FIG. 19 is a conceptual diagram illustrating a sixth exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 19 , a slot may include three DL symbols, nine FLsymbols, and two UL symbols. The base station may inform the terminal ofconfiguration information of FL symbols used for DL sub-slots andconfiguration information of FL symbols used for UL sub-slots usinghigher layer signaling. Consecutive five FL symbols after the DL symbolsmay be used to configure DL sub-slots. Accordingly, eight symbols may beused to configure DL sub-slots. Consecutive two FL symbols before the ULsymbols may be used to configure UL sub-slots. Accordingly, four symbolsmay be used to configure UL sub-slots. DL data channel candidatesbelonging to the DL sub-slots may be considered valid.

In a proposed method, boundaries of sub-slots may be derived based onthe number of sub-slots or the sub-slot pattern.

In a proposed method, the base station may transmit informationindicating the boundaries of the sub-slots to the terminal through acombination of one or more among higher layer signaling, MAC CE, andDCI. When L sub-slots (e.g., sub-slots 1 to L) are configured in oneslot, since the sub-slot 1 is configured in the first symbol (e.g.symbol 0, the first symbol other than the DL symbols, or an arbitrarysymbol of the FL symbols) of the slot, a signaling operation indicatingthe sub-slot 1 may be unnecessary. The signaling operation of a startsymbol index of the sub-slots 2 to L may be necessary.

For example, the base station may inform the terminal of (S₁, S₂, . . ., S_(L)) or (S₁, S₂, . . . , S_(L-1)). Alternatively, the base stationmay inform the terminal of (L, S₁, S₂, . . . , S_(L)) or (L, S₁, S₂, . .. , S_(L-1)). Alternatively, the base station may inform the terminal ofend symbol indexes of the sub-slots. Alternatively, the base station mayinform the terminal of the lengths of the sub-slots (e.g., the numbersof symbols included in the sub-slots). In the above exemplaryembodiments, L−1 or more symbol indexes may be signaled from the basestation to the terminal.

Meanwhile, the complexity of implementation may be increased at the basestation and the terminal by the signaling operations of the L−1 or Lsymbol indexes. In a proposed method, the sub-slot patterns may beindicated in form of indexes. When the sub-slot patterns are predefined,the base station may transmit an index of the sub-slot pattern to theterminal through a combination of one or more among higher layersignaling, MAC CE, and DCI. The index of the sub-slot pattern mayindicate the number of sub-slots included in the slot, the numbers ofsymbols included in the sub-slots, and/or the boundaries of thesub-slots. Even when the number of sub-slots included in the slot is thesame, if the numbers of symbols included in the sub-slots are different,the arrangement of the sub-slots within the slot may be different.

For example, in Table 2, a sub-slot pattern may be defined based on astart symbol of the sub-slot, and in Table 3, a sub-slot pattern may bedefined based on the number of symbols included in the sub-slot. InTable 3, when the number of (FL symbols+UL symbols) included in the slotis less than 14, the number of sub-slots may be counted from an end ofthe slot toward a start of the slot. In this case, the start symbol ofthe sub-slot 1 may not be the symbol 0 of the slot.

In Table 3, when the number of (DL symbols+FL symbols) included in theslot is less than 14, the number of sub-slots may be counted from thestart of the slot toward the end of the slot. In this case, the endsymbol of the sub-slot L may not be the symbol 13 of the slot. Even whenthe number of sub-slots is the same in Tables 2 and 3, the number ofsymbols included in each of the sub-slots may be different. The basestation may inform the terminal of the index of the sub-slot pattern toreduce the signaling overhead of the sub-slot pattern.

In Tables 2 and 3, the indexes 2, 3, and 4 may indicate differentsub-slot patterns. In the sub-slot pattern indicated by the index 2, thenumbers of symbols included in sub-slots 3 and 4 may be greater than thenumbers of symbols included in other sub-slots. In this case, the numberof DL data channel candidates to be mapped to the sub-slots 3 and 4 maybe larger than the number of DL data channel candidates to be mapped tothe sub-slots 1 and 2. The number of HARQ responses in the sub-slots 3and 4 may be greater than the number of HARQ responses in the sub-slots1 and 2, and if the UL control channels use the same bandwidth, thelength of the UL control channel corresponding to the sub-slots 3 and 4may be longer than the length of the UL control channel corresponding tothe sub-slots 1 and 2.

In the sub-slot pattern indicated by the index 3 of Table 2 and Table 3,the numbers of symbols included in the sub-slots 1 and 2 may be largerthan the numbers of symbols included in other sub-slots. In this case,the number of DL data channel candidates to be mapped to the sub-slots 1and 2 may be larger than the number of DL data channel candidates to bemapped to the sub-slots 3 and 4. A time required for feedback of an HARQresponse in the sub-slots 3 and 4 may be secured.

In the sub-slot pattern indicated by the index 4 of Tables 2 and 3, thenumbers of symbols included in the sub-slots 2 and 4 may be greater thanthe numbers of symbols included in other sub-slots. In this case, thesub-slot pattern may have a symmetrical characteristic. When asubcarrier spacing (e.g., 15 kHz or 30 kHz) of the DL data channel isdifferent from a subcarrier spacing (e.g., 30 kHz or 60 kHz) of the ULcontrol channel, in order to indicate a time unit for feeding back anHARQ response, it is preferable that the boundary of the sub-slotbelongs to the boundary of the symbol.

In addition to the subcarrier spacing, the number of symbols included inthe slot may vary according to the type of a cyclic prefix (e.g., anormal CP or an extended CP). When the normal CP is used, the number ofsymbols included in the slot may be fourteen. When the extended CP isused, the number of symbols included in the slot may be twelve. In thiscase, the corresponding sub-slot pattern may be derived from thesub-slot pattern for the reference BWP. Alternatively, indexesindicating sub-slot patterns to which the extended CP is applied may befurther defined.

In the sub-slot pattern indicated by the index 5 of Tables 2 and 3, thenumber of symbols included in the sub-slot 1 may be greater than thenumbers of symbols included in other sub-slots. In this case, in theprocedure of assigning DL data channels, the processing time of theterminal may be secured based on the last symbol of the DL data channeland the start symbol of the UL control channel for feedback of the HARQresponse for the DL data channel.

The last symbol of the TDRA may typically be located in a back regionrather than a front region of the slot. In this case, the number of DLdata channels corresponding to the sub-slot for the feedback of the HARQresponse may be large in the sub-slot located in the back region of theslot. In this case, the size (e.g., number of bits) of the HARQ responseincluded in the UL control channel may be asymmetric, and the receptionquality of the HARQ response at the base station may vary depending onthe TDRA. To solve this problem, the number of symbols belonging to thesub-slot 1 may be increased. Alternatively, the length of symbolsbelonging to the sub-slot 1 may be increased.

In the sub-slot pattern indicated by the index 6 of Tables 2 and 3, foursub-slots may be configured in one slot. (L₁+L₂) may be the same as(L₃+L₄). That is, each of (L₁+L₂) and (L₃+L₄) may be seven. This isbecause BWPs with different subcarrier spacing (e.g., BWP with 15 kHzsubcarrier spacing and BWP with 30 kHz subcarrier spacing, or BWP with30 kHz subcarrier spacing and BWP with 60 kHz subcarrier spacing) may bemultiplexed in the frequency domain or time domain. The boundary of thesub-slot(s) may be configured to be the boundary of half of the slot.

In the sub-slot pattern indicated by the index 7 of Table 2 and Table 3,seven sub-slots may be configured in one slot. Each of the sevensub-slots may include two symbols.

In a proposed method, a DL sub-slot pattern may be configured to beequal to a UL sub-slot pattern. Alternatively, the DL sub-slot patternmay be configured independently of the UL sub-slot pattern. For example,the DL sub-slot pattern may be different from the UL sub-slot pattern.

FIG. 20 is a conceptual diagram illustrating a seventh exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 20 , a sub-slot pattern may be defined, a DL sub-slotcomprising DL symbols and FL symbols may be configured based on asub-slot pattern, and a UL sub-slot comprising UL symbols and FL symbolsmay be configured based on a sub-slot pattern. If a sub-slot patternaccording to the numerology of the reference BWP is defined, thesub-slot pattern may be applied to both the DL sub-slot and the ULsub-slot.

For example, a slot n may include four sub-slots. The base station mayinform the terminal of the sub-slot pattern through a combination of oneor more among higher layer signaling, MAC CE, and DCI, regardless oftransmission of a DL data channel or transmission of a UL controlchannel. The sub-slot pattern may be applied to the communication systemsupporting the FDD scheme. The DL sub-slot pattern applied to the DLslot may be the same as the UL sub-slot pattern applied to the UL slot.This pattern may be preferably applicable in systems operating in theFDD scheme. That is, the pattern of the DL sub-slot applied to the DLslot may be the same as the pattern of the UL sub-slot applied to the ULslot.

However, in the communication system supporting the TDD scheme, the DLsub-slot pattern applied to the DL data channel may be configureddifferently from the UL sub-slot pattern applied to the UL controlchannel. This is because DL data channel candidates and UL controlchannel candidates may be valid only in a specific sub-slot. If an HARQresponse codebook with a semi-static size is used, the size of the HARQresponse codebook may not be uniform according to the number of TDRAindexes, the slot offset (or, sub-slot offset) of the HARQ response, andthe format of the slot to which the DL data channel is allocated.

In a proposed method, the slot offset (or, sub-slot offset) for the HARQresponse may be calculated based on the last UL sub-slot among ULsub-slots located at the same timing as the DL sub-slot to which the DLdata channel belongs. The base station may inform the terminal of theslot offset (or, sub-slot offset) for the HARQ response through acombination of one or more among higher layer signaling, MAC CE, andDCI.

Referring back to FIG. 18 , FL symbols may be included in a DL sub-slotand/or a UL sub-slot. A specific DL data channel (e.g., DL data channelcorresponding to TDRA index 7) may belong to the DL sub-slot 2, and atiming (e.g., start timing) of the DL sub-slot 2 is the same as a timing(e.g., start timing) of the UL sub-slot 0. When the slot includes alarge number of FL symbols, some DL sub-slots may be located after theUL sub-slot. In this case, a reference sub-slot for calculating a slotoffset (or sub-slot offset) for an HARQ response may be needed.

FIG. 21 is a conceptual diagram illustrating an eighth exemplaryembodiment of a sub-slot pattern in a communication system.

Referring to FIG. 21 , a reference DL sub-slot may be a DL sub-slot towhich a DL data channel is assigned, and a reference UL sub-slot may bederived from the reference DL sub-slot. When the length of the DLsub-slot is different from the length of the UL sub-slot or when thestart timing of the DL sub-slot is different from the start timing ofthe UL sub-slot, the reference DL sub-slot may correspond to a pluralityof UL sub-slots. In this case, a slot offset (or sub-slot offset) for anHARQ response may be determined based on the last UL sub-slot among theplurality of UL sub-slots. The time resource for feedback of the HARQresponse to the PDSCH may be determined based on the UL sub-slot x+1.That is, the UL sub-slot x+1 may be the reference UL sub-slot. When theslot offset or sub-slot offset configured by the base station is K, theterminal may transmit a UL control channel or a UL data channelincluding the HARQ response in the UL sub-slot x+1+K.

When one sub-slot pattern is configured without distinguishing the DLsub-slot and the UL sub-slot, the time resource for feedback of the HARQresponse may be derived based on the sub-slot to which the DL datachannel belongs.

In a proposed method, a UCI piggyback timing may be limited to a portionor instance of a PUSCH.

An HARQ response codebook may correspond one-to-one with a resource ofone PUCCH. The priority of the HARQ response codebook may be the same asthe priority of the PDSCH. The HARQ response codebook may be generatedin consideration of PDSCHs having the same priority. For example, if thePDSCH is dynamically assigned and the HARQ response codebook for theURLLC PDSCH (or eMBB PDSCH) is transmitted on the PUSCH or the PUCCH,the priority of the HARQ response codebook (or PDSCH) may be consideredas the priority of URLLC (or eMBB). The URLLC PDSCH may be a PDSCHtransmitted according to the requirements of the URLLC service, and theeMBB PDSCH may be a PDSCH transmitted according to the requirements ofthe eMBB service.

When a feedback resource of the HARQ response (e.g., URLLC PUCCH) forthe URLLC PDSCH overlaps with the URLLC PUSCH in the time domain, theHARQ response may be transmitted as multiplexed with the URLLC PUSCH.When the URLLC PUCCH is configured in a sub-slot and the URLLC PUSCH isconfigured in a time duration longer than the sub-slot, the URLLC PUSCHmay overlap two or more URLLC PUCCHs. When the HARQ response codebook isgenerated on a slot basis, if the PUSCH overlaps with one PUCCH in thetime domain, the UCI may be multiplexed in the PUSCH. This method maynot be applied when the HARQ response codebook is generated on asub-slot basis.

In a proposed method, HARQ response codebooks corresponding to two ormore sub-slots may be concatenated in order of the sub-slots (e.g., theorder of the PDSCHs associated with the HARQ response codebook or theorder of the PDCCHs scheduling the PDSCHs associated with the HARQresponse codebook), and the concatenated HARQ response codebooks may bean HARQ response bit string. The HARQ response bit string may be mappedto the PUSCH. Here, the PDSCHs associated with the HARQ responsecodebook and the PDCCHs scheduling the PDSCHs associated with the HARQresponse codebook may be configured on a sub-slot basis, and the PUSCHto which the HARQ response bit string is mapped may be configured inunits of a slot comprising two or more sub-slots. The base station mayknow in advance the HARQ response bit string to be generated by theterminal. Accordingly, the base station may determine one or more of thesize of the uplink-shared channel (UL-SCH), the size of the aperiodicCSI, and the resource size of the PUSCH in consideration of the size ofthe HARQ response bit string (or, the number of HARQ response bitstrings). The base station may transmit a UL grant indicating one ormore of the size of the UL-SCH, the size of the aperiodic CSI, and theresource size of the PUSCH to the terminal. The terminal may receive theUL grant from the base station, and may identify a DAI and a beta offsetused for UCI multiplexing from the UL grant.

FIG. 22 is a conceptual diagram illustrating a first exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 22 , one PUSCH may be transmitted through two or moresub-slots. In this case, the terminal may configure two HARQ responsecodebooks into one HARQ response bit string and multiplex the HARQresponse bit string with the PUSCH.

An HARQ response codebook 1 may be encoded at the same timing with anHARQ response codebook 2 generated after the HARQ response codebook 1.Therefore, the terminal should decode the PDSCH corresponding to theHARQ response codebook 2 quickly. In order to support the encodingoperation of the HARQ response codebooks 1 and 2 at the same time as thefast decoding operation of the PDSCH corresponding to the HARQ responsecodebook 2, the base station may perform a scheduling operation for thePDSCH and the PUSCH. When the PUSCH is transmitted according to afrequency hopping scheme, the HARQ response bit string may bemultiplexed at every hop of the PUSCH. Accordingly, the base station mayperform a decoding operation on the HARQ response bit string afterreceiving the PUSCH (e.g., part of the PUSCH) in the second hop.

Meanwhile, when a large amount of time is required for the decodingoperation of the PDSCH, it may be difficult to simultaneously schedulethe PDSCH and the PUSCH. Therefore, instead of making HARQ responsecodebooks into one HARQ response bit string, each HARQ response codebookmay be multiplexed with the PUSCH in a time resource adjacent to asub-slot in which the corresponding HARQ response codebook is to betransmitted. For example, the HARQ response codebook 1 may bemultiplexed in the radio resource overlapping or adjacent to the PUCCHassociated with the HARQ response codebook 1 among the radio resourcesoccupied by the PUSCH. The HARQ response codebook 2 may be multiplexedin the radio resource overlapping or adjacent to the PUCCH associatedwith the HARQ response codebook 2 among the radio resources occupied bythe PUSCH

FIG. 23 is a conceptual diagram illustrating a second exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 23 , when a PUSCH is transmitted in a frequencyhopping scheme, an HARQ response codebook may be multiplexed with thePUSCH on a frequency hop basis. When the PUSCH belongs to a differentsub-slot per frequency hop, the HARQ response codebook may be mappeddifferently for each frequency hop. In this case, the HARQ responsecodebook 1 may be multiplexed in the PUSCH of the first hop, and theHARQ response codebook 2 may be multiplexed in the PUSCH of the secondhop. When two or more HARQ response codebooks are multiplexed in thePUSCH of one hop, the terminal may concatenate the HARQ responsecodebooks based on the order of the sub-slots (e.g., the sub-slotsassociated with the HARQ response codebooks) to generate the HARQresponse bit string. The terminal may multiplex the HARQ response bitstring in the PUSCH of one hop.

Multi-Reception Point (RxP)

In a communication scenario in which the terminal transmits PUSCHsthrough different RxPs, a PUSCH occasion may be configured. One PUSCHoccasion may be indicated by one UL grant. The PUSCH occasion may bePUSCH instances consecutive in the time domain. A TB and ademodulation-reference signal (DM-RS) may be mapped to the PUSCHinstance. The same TB may be mapped to PUSCH instances. Alternatively, adifferent TB may be mapped to each of the PUSCH instances. When the sameTB is mapped to the PUSCH instances, a redundancy version (RV) may beconfigured differently for each PUSCH instance.

In this case, the base station may instruct the terminal to perform atransmission operation of a PUCCH. In a proposed method, each of thePUSCH instances may be regarded as an independent UL transmission, andUCI may be multiplexed in each of the PUSCH instances. If themini-slot(s) in which the PUSCH instance is transmitted belongs to aspecific sub-slot(s), the UCI may be multiplexed in the correspondingPUSCH instance.

FIG. 24 is a conceptual diagram illustrating a third exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 24 , one PUSCH occasion may include four PUSCHinstances. The UCI may be multiplexed in the PUSCH instance 1 and thePUSCH instance 3. The HARQ response codebook 1 may be multiplexed in thePUSCH instance 1, and the HARQ response codebook 2 may be multiplexed inthe PUSCH instance 3.

The PUCCH on which the HARQ response codebook 2 is to be transmitted mayoverlap with the PUSCH instances 3 and 4 in the time domain. Since thePUSCH instance 3 is located first in time among the PUSCH instances 3and 4 overlapping with the PUCCH, the terminal may multiplex the HARQresponse codebook 2 in the PUSCH instance 3. When a frequency hoppingscheme is applied to the PUSCH instance, the UCI (e.g., HARQ responsecodebook) may be multiplexed in the corresponding frequency hop.Alternatively, the UCI (e.g., HARQ response codebook) may be multiplexedregardless of frequency hopping.

In a proposed method, a reference of the processing time for the UCImultiplexing may be the first symbol of the PUSCH (e.g., PUSCH in whichthe UCI is multiplexed). The terminal may transmit the PUSCH using onlyinformation included in the UL grant. Accordingly, the terminal maygenerate the PUSCH based on the size of the UL-SCH/CSI indicated by theUL grant without considering the slot format and/or the UCI multiplexingoperation.

When the UCI is multiplexed in the PUSCH, it may be assumed that theterminal does not receive DL assignment information (e.g., DAI) afterreceiving the UL grant. The terminal may estimate the size of the UCIbased on a field included in the UL grant, and may perform a puncturingoperation or a rate matching operation on the UL-SCH based on the sizeof the UCI.

In order for the UCI to be multiplexed with the PUSCH, the processingtime of the terminal should be sufficiently secured. When the UCI is anHARQ response, an interval between the last symbol of the PDSCHdynamically assigned by the DCI and the start symbol of the PUSCH may beequal to or longer than a time interval proportional to the predefinednumber of symbols (e.g., N₁+d_(1,1)+1). An interval between the lastsymbol of the SPS PDSCH semi-statically assigned and the start symbol ofthe PUSCH may be equal to or longer than a time interval proportional tothe predefined number of symbols (e.g., N+1).

An interval between the last symbol of the PDSCH and the start symbol ofthe PUSCH (e.g., UL-SCH) dynamically assigned by the DCI may be equal toor longer than a time interval proportional to the predefined number ofsymbols (e.g., N₂+d₂,i+1). An interval between the last symbol of thePDSCH and the start symbol of the PUSCH (e.g., CSI) dynamically assignedby the DCI may be equal to or longer than a time interval proportionalto the number of predefined symbols (e.g., Z+d).

N, N₁, N₂, d_(1,1), and d_(2,1) may be defined in the 3GPP technicalspecification. The base station may inform the terminal of N, N₁, N₂,d_(1,1), and d_(2,1) through a combination of one or more among higherlayer signaling, MAC CE, and DCI. In the above-described exemplaryembodiments, the time required to generate the PUSCH may be as follows.The UCI processing operation of the terminal before the required timemay be distinguished from the UCI processing operation of the terminalafter the required time.

FIG. 25 is a conceptual diagram illustrating a fourth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 25 , PUSCH transmission may be performed withoutfrequency hopping, and one PUSCH may overlap with a plurality of PUCCHs.In this case, the HARQ response codebooks 1 and 2 may be multiplexed inthe PUSCH. A time budget may be a time required at the terminal for theUCI processing (e.g., UCI transmission).

FIG. 26 is a conceptual diagram illustrating a fifth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 26 , PUSCH transmission may be performed based on afrequency hopping scheme, and the PUSCH may overlap with a PUCCH. Inthis case, the HARQ response codebook 1 may be multiplexed in the PUSCHof the first hop, and the HARQ response codebook 2 may be multiplexed inthe PUSCH of the second hop. A time budget 1 may be a time required atthe terminal for processing UCI 1 (e.g., HARQ response codebook 1), anda time budget 2 may be a time required at the terminal for processingUCI 2 (e.g., HARQ response codebook 2).

FIG. 27 is a conceptual diagram illustrating a sixth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 27 , one PUSCH occasion may include four PUSCHinstances. The HARQ response codebook 1 may be multiplexed in the PUSCHinstance 1, and the HARQ response codebook 2 may be multiplexed in thePUSCH instance 3. A time budget 1 may be a time required at the terminalfor processing UCI 1 (e.g., HARQ response codebook 1), and a time budget2 may be a time required at the terminal for processing UCI 2 (e.g.,HARQ response codebook 2).

In order to apply the above-described methods, the start symbol of thePUSCH and the last symbol of the PDSCH, which the terminal interprets,should be changed. For example, the terminal may calculate a processingtime (e.g., time budget) based on a frequency hop or PUSCH instance ofthe PUSCH in which the UCI is multiplexed. In the exemplary embodimentshown in FIG. 26 , a processing time (e.g., time budget) may becalculated based on a frequency hop of a PUSCH on one HARQ responsecodebook basis. In the exemplary embodiment shown in FIG. 27 , aprocessing time (e.g., time budget) may be calculated based on a PUSCHinstance on one HARQ response codebook basis. These methods differ fromthe method of calculating the processing time based on the first symbolof the PUSCH.

Since the references (e.g., frequency hop or PUSCH instance) forcalculating the processing time (e.g., time budget) are different in theexemplary embodiments illustrated in FIGS. 25 to 27 , a timing ofgenerating the UCI multiplexed in the PUSCH may also be changed. Forexample, the last symbol of the PDSCH may be located before the timebudget from the first symbol of the PUSCH in which the UCI ismultiplexed. In the exemplary embodiments shown in FIGS. 25 to 27 , theUL grant is received after the DL assignment information, but the ULgrant may be received before the DL assignment information.

In a proposed method, when the processing time is insufficient in theterminal or when DL assignment information is received after the ULgrant, the terminal may select on UL channel, and then transmit the UCIin the selected UL channel.

The priority of the UL-SCH may be different from the priority of theDL-SCH. The priority of the DL-SCH/UL-SCH may be dynamically indicated.Alternatively, the priority of DL-SCH/UL-SCH may be indicated by higherlayer signaling. The priority of DL-SCH/UL-SCH may be dynamicallyindicated by a PDCCH (e.g., DCI) assigning the DL-SCH/UL-SCH or an RNTI.The priority of the DL-SCH may be the priority of the PDSCH, and thepriority of the UL-SCH may be the priority of the PUSCH.

The terminal may identify the priority of the DL-SCH/UL-SCH based on asearch space or a control resource set (CORESET) in which thecorresponding PDCCH is detected. The terminal may identify the priorityof the DL-SCH/UL-SCH based on a specific field of the DCI. The terminalmay identify the priority of the DL-SCH/UL-SCH based on thecharacteristics of the PDCCH (e.g., DCI format, DCI size). Two or morepriorities may be defined. If two priorities are defined, the twopriorities may be referred to as a low priority and a high priority.

The above-described method of multiplexing UCI (e.g., HARQ response,CSI) and PUSCH may be applied when the priority of UCI (e.g., DL-SCHassociated with UCI) is the same as that of UL-SCH. When the priority ofthe DL-SCH is lower than the priority of the UL-SCH, an HARQ responsefor the DL-SCH may not be multiplexed in the UL-SCH. Regardless of thereception timing of the DL assignment information and the UL grant, themultiplexing operation of the UCI may not be performed when the priorityof the DL-SCH associated with the UCI is different from the priority ofthe UL-SCH. When the priority of the DL-SCH is lower than the priorityof the UL-SCH, the terminal may transmit the PUSCH according to the ULgrant, and the HARQ response may not be multiplexed in the correspondingPUSCH. When the PUCCH overlaps with the PUSCH in the time domain, thePUCCH may not be transmitted. In this case, since the HARQ response isnot received from the terminal, the base station may retransmit theDL-SCH using the new DL assignment information.

When the priority of the DL-SCH is higher than the priority of theUL-SCH, the terminal may transmit a PUCCH including an HARQ responseassociated with the DL-SCH. Regardless of the reception timing of the DLassignment information and the UL grant, the multiplexing operation ofthe UCI may not be performed when the priority of the DL-SCH associatedwith the UCI is different from the priority of the UL-SCH. Accordingly,the terminal may transmit the PUCCH based on the DL assignmentinformation. When the PUCCH overlaps with the PUSCH in the time domain,the PUSCH may not be transmitted. In this case, since the PUSCH is notreceived from the terminal, the base station may trigger aretransmission operation of the UL-SCH using a new UL grant.

When the priority of the DL-SCH is the same as that of the UL-SCH, andthe processing time (e.g., time budget) is satisfied at the terminal,the UCI associated with the DL-SCH may be multiplexed with the UL-SCH.However, the base station cannot request transmission of the HARQresponse for the DL-SCH after allocating a UL-SCH transmission resourceto the terminal. Therefore, the scheduling operation of the DL-SCH maybe limited. In order to support the URLLC services, this limitationneeds to be relaxed.

The base station may transmit DL assignment information for the PDSCHassociated with the HARQ response to the terminal so that the PUCCH forfeedback of the HARQ response does not overlap the PUSCH. Alternatively,the assignment timing of the PDSCH may be delayed. Since thetransmission of the DL-SCH is delayed according to these operations, therequirements of the URLLC service may not be satisfied.

The operation of generating the PUSCH based on the information indicatedafter the UL grant may be difficult to be implemented in the terminal.Therefore, methods that satisfy the following conditions are needed.

Condition 1: Easy to implement in terminal

Condition 2: Terminal can generate a PUSCH only with a UL grant

Condition 3: Base station can perform flexible scheduling for a PDSCH

In a proposed method, it may be allowed that the transmission timing ofthe UL grant is changed with the transmission timing of the DLassignment information. When the priority of the DL-SCH is the same asthe priority of the UL-SCH, the terminal may perform communication basedon the DL assignment information received after the UL grant. Forexample, the terminal may receive the UL grant and may receive the DLassignment information after the UL grant. When the PUCCH associatedwith the DL assignment information overlaps with the PUSCH indicated bythe UL grant in the time domain, the terminal may transmit the PUCCH orthe PUSCH to the base station. Therefore, there may be no transmissionrestriction of the DL assignment information at the base station.

In a proposed method, the terminal may select a UL channel(s) before thelast UL channel among the plurality of UL channels, and perform uplinkcommunication using the selected UL channel(s). That is, the terminalmay not use the last UL channel. The terminal may compare the positionof the first symbol in the resources to which the DL assignmentinformation assigning the PDSCH is mapped with the positions of thefirst symbols in the resources to which the UL grant is mapped, andbased on the comparison result, the terminal may select a UL channel theis temporally advanced among the UL channels (e.g., PUCCH and PUSCHassociated with the PDSCH). The UL channel selected by the terminal maybe a PUCCH or a PUSCH.

FIG. 28 is a conceptual diagram illustrating a seventh exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 28 , the base station may transmit a UL grant aftertransmitting DL assignment information for a PDSCH. The terminal mayreceive the DL assignment information from the base station, and mayreceive the PDSCH based on the DL assignment information. In addition,the terminal may receive the UL grant from the base station, and mayidentify a PUSCH indicated by the UL grant. Here, a PUCCH on which anHARQ response for the PDSCH is to be transmitted may overlap with thePUSCH in the time domain. When the UL grant is received before thePDSCH, the terminal may multiplex the HARQ response for the PDSCH withthe PUSCH.

FIG. 29 is a conceptual diagram illustrating an eighth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 29 , the base station may transmit a UL grant aftertransmitting DL assignment information for a PDSCH. The terminal mayreceive DL assignment information from the base station, and may receivethe PDSCH based on the DL assignment information. In addition, theterminal may receive the UL grant from the base station, and mayidentify a PUSCH indicated by the UL grant. Here, a PUCCH on which anHARQ response for the PDSCH is to be transmitted may overlap with thePUSCH in the time domain. When the DL assignment information is receivedbefore the UL grant, the terminal may drop the PUSCH transmissionscheduled by the UL grant, and transmit the PUCCH including the HARQresponse to the PDSCH to the base station.

FIG. 30 is a conceptual diagram illustrating a ninth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 30 , the base station may transmit DL assignmentinformation for a PDSCH after transmitting a UL grant. The terminal mayreceive the UL grant from the base station, and may identify a PUSCHindicated by the UL grant. In addition, the terminal may receive the DLassignment information from the base station, and receive the PDSCHbased on the DL assignment information. Here, a PUCCH on which an HARQresponse for the PDSCH is to be transmitted may overlap with the PUSCHin the time domain. When the UL grant is received before the DLassignment information, the terminal may transmit the PUSCH scheduled bythe UL grant, and may drop transmission of the PUCCH. The HARQ responsefor the PDSCH may be multiplexed in the PUSCH.

Here, the base station may know in advance that the terminal does nottransmit the PUCCH including the HARQ response for the PDSCH. In thiscase, since the terminal performs a decoding operation on the PDSCH(e.g., DL-SCH), when the base station transmits DL assignmentinformation for triggering retransmission of the PDSCH, the terminal mayexpect that the error rate of the PDSCH is reduced.

In another proposed method, the terminal may transmit the last ULchannel among the plurality of UL channels, and the transmission of theUL channel before the last UL channel among the plurality of UL channelsmay be cancelled.

The terminal may compare the position of the first symbol in theresources to which the DL assignment assigning the PDSCH is mapped withthe position of the first symbols in the resources to which the UL grantassigning the PUSCH is mapped, and based on the comparison result, theterminal may select the last UL channel in the time domain among the ULchannel (e.g., PUCCH and PUSCH associated with PDSCH). The UL channelselected by the terminal may be a PUCCH or a PUSCH.

The UL channel assigned by the base station may be a UL channel thatshould be urgently transmitted. Therefore, according to the proposedmethod, the terminal may transmit the last UL channel in the timedomain. The transmission of the UL channel before the last UL channel inthe time domain may be canceled.

FIG. 31 is a conceptual diagram illustrating a tenth exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 31 , the base station may transmit DL assignmentinformation for a PDSCH after transmitting a UL grant. The terminal mayreceive the UL grant from the base station, and may identify the PUSCHindicated by the UL grant. In addition, the terminal may receive the DLassignment information from the base station, and may receive the PDSCHbased on the DL assignment information. Here, a PUCCH on which an HARQresponse for the PDSCH is to be transmitted may overlap with the PUSCHin the time domain. When the UL grant is received before the DLassignment information, the terminal may transmit the PUCCH includingthe HARQ response for the PDSCH scheduled by the DL assignmentinformation. That is, the transmission of the PUSCH scheduled by the ULgrant may be dropped.

FIG. 32 is a conceptual diagram illustrating an eleventh exemplaryembodiment of a feedback method of an HARQ response in a communicationsystem.

Referring to FIG. 32 , the base station may transmit a UL grant aftertransmitting DL assignment information for a PDSCH. The terminal mayreceive the DL assignment information from the base station, and mayreceive the PDSCH based on the DL assignment information. In addition,the terminal may receive the UL grant from the base station, and mayidentify a PUSCH indicated by the UL grant. Here, a PUCCH on which anHARQ response for the PDSCH is to be transmitted may overlap with thePUSCH in the time domain. When the DL assignment information is receivedbefore the UL grant, the terminal may transmit the PUSCH scheduled bythe UL grant. That is, the transmission of the PUCCH including the HARQresponse for the PDSCH scheduled by the DL assignment information may bedropped. The HARQ response for the PDSCH may be multiplexed in thePUSCH.

When the PUSCH is assigned after the PUCCH is assigned, the terminal maynot transmit the PUCCH and may transmit the PUSCH. If the HARQ responsefor the PDSCH is not received from the terminal, the base station cannotconfirm whether the PDSCH has been successfully received at theterminal. Accordingly, the base station may regard the case in which theHARQ response for the PDSCH is not received as a case where a NACK isreceived, and may transmit DL assignment information for the PDSCHagain.

In a proposed method, an HARQ response codebook may be generatedconsidering different RxPs.

The terminal may generate an HARQ response codebook based on the 3GPPtechnical specification. The base station may transmit to the terminalDL-DCIs instructing to transmit PUCCHs in the same time resources. TheDL-DCI may include scheduling information of the PDSCH. The DL-DCI maybe distinguished from the UL-DCI including the UL grant.

The terminal may receive the DL-DCIs from the base station, and mayarrange HARQ response bits based on the reception order of the DL-DCIs.The terminal may generate an HARQ response codebook by concatenating theHARQ response bits.

One HARQ response codebook may include the HARQ response bits to betransmitted on the PUCCH of the same sub-slot. One HARQ responsecodebook may have a form of a bitmap. The HARQ response codebook maycorrespond one-to-one with the sub-slot.

The PUCCHs corresponding to the HARQ response codebook may have the sametransmission configuration indicator (TCI) or the same schedulingrequest indicator (SRI). Alternatively, the PUCCHs corresponding to theHARQ response codebook may have different TCIs or different SRIs. TheTCI may be used for the DL transmissions as well as the ULtransmissions. The TCI may mean information of a preprocessing and/orbeamforming for transmissions (e.g., DL transmission, UL transmissions).The SRI may mean a sounding reference signal resource indicator. The TCIand SRI may be used interchangeably. Alternatively, other term may beused instead of the TCI and SRI.

The terminal may assume that HARQ response codebooks having the same TCI(or SRI) are received at the same RxP (e.g., base station). The terminalmay assume that HARQ response codebooks having different TCIs (or SRIs)are received at different RxPs (e.g., base stations). The TCI may beobtained from configuration information of the CORESET in which theDL-DCI scheduling the PDSCH is received. The base station may transmitthe configuration information of the CORESET to the terminal usinghigher layer signaling. The configuration information of the CORESET mayinclude one or more of TCI, SRI used for PUCCH transmission, andinformation indicating a preprocessing scheme. Accordingly, the PUCCHmay have a TCI of the CORESET associated with the corresponding PUCCH.

The base station may perform a PDSCH scheduling operation so that thePUCCHs having the same TCI are located in the same sub-slot. Arrangingthe RxPs in order may be equivalent to arranging the CORESET indexes inorder. If there is only one sub-slot, an algorithm defined in Table 4below may be used.

TABLE 4 For CORESET index    For Serving cell index     For schedulingDL-DCI order        Place the HARQ-ACK bit.     End scheduling DL-DCIindex    End Serving cell index End CORESET index

If a reception timing of DL-DCI 1 is earlier than a reception timing ofDL-DCI 2, an HARQ response bit associated with DL-DCI 1 in the HARQresponse codebook may be located before an HARQ response bit associatedwith DL-DCI 2. If there are two or more sub-slots, the following methodsmay be considered.

In a proposed method, sub-slots may be considered first, and RxPs may beconsidered later. The terminal may generate an HARQ response codebookbased on the 3GPP technical specification. The terminal may receiveDL-DCIs indicating that PUCCHs are transmitted in the same timeresources, and may arrange HARQ response bits based on the order ofreceiving the DL-DCIs. The terminal may generate the HARQ responsecodebook by concatenating the HARQ response bits in the order of theserving cells.

When the PUCCHs corresponding to the HARQ response codebook have thesame TCI, the terminal may generate an HARQ response bit string A byconcatenating the HARQ response codebooks in the order of sub-slots. Theterminal may generate an HARQ response bit string B by concatenating aplurality of HARQ response bit string A in the order of the servingcells. The terminal may map the HARQ response bit string B to a PUSCH ora PUCCH.

When the PUCCHs corresponding to the HARQ response codebook havedifferent TCIs, the HARQ response codebooks may not be concatenatedregardless of the sub-slots. The terminal may generate an HARQ responsebit string A by concatenating the HARQ response codebooks in the orderof the serving cells. The terminal may generate an HARQ response bitstring B by concatenating a plurality of HARQ response bit string A inthe order of TCIs (e.g., in the order of CORESETs). The HARQ responsebit string B may be mapped to a PUSCH or a PUCCH.

When the above-described procedure is used, the terminal may generatethe HARQ response codebook by arranging HARQ responses fed back in thesame sub-slot. Thereafter, the terminal may generate an HARQ responsebit string A by concatenating the HARQ response codebooks having thesame TCI in the order of sub-slots. Thereafter, the terminal maygenerate an HARQ response bit string B by concatenating a plurality ofHARQ response bit string A in the order of the serving cells.Thereafter, the terminal may generate an HARQ response bit string C byconcatenating a plurality of HARQ response bit string B in the order ofCORESETs. Thereafter, the terminal may map the HARQ response bit stringC to a PUSCH or a PUCCH. This procedure may be performed based on analgorithm defined in Table 5 below.

TABLE 5 For CORESET index    For Sub-slot index     For Serving cellindex       For scheduling DL-DCI order           Place the HARQ-ACKbit.       End scheduling DL-DCI index     End Serving cell index    EndSub-slot index End CORESET index

In a proposed method, the time order may be considered first, then thefrequency order may be considered, and finally the RxP order may beconsidered. The terminal may generate the HARQ response codebook inconsideration of the time order and the frequency order. If the RxP isfurther considered in the generation procedure of the HARQ responsecodebook, the HARQ response codebooks may be concatenated in the orderof CORESETs.

The HARQ response bit string A may be generated according to a conceptextended based on the time order. For example, the order of the PDSCHmay be determined by the reception order of the DL-DCI scheduling thePDSCH. Here, the DL-DCI may be limited to a DL-DCI indicating atransmission timing of the same PUCCH. The terminal may generate theHARQ response bit string B by concatenating a plurality of HARQ responsebit string A according to the transmission order of the PUCCHs (e.g.,the order of sub-slots). Thereafter, the terminal may generate the HARQresponse bit string C by concatenating a plurality of HARQ response bitstring B in the order of the serving cells. Thereafter, the terminal maygenerate an HARQ response bit string D by concatenating a plurality ofHARQ response bit strings C in the order of CORESETs. The HARQ responsebit string D may be multiplexed in a PUCCH or a PUSCH. This proceduremay be performed based on an algorithm defined in Table 6 below.

TABLE 6 For CORESET index    For Serving cell index     For Sub-slotindex      For scheduling DL-DCI order       Place the HARQ-ACK bit.     End scheduling DL-DCI index     End Sub-slot index    End Servingcell index End CORESET index

According to a proposed method, since the last concatenation operationis performed in the order of CORESETs, when different PUCCHs aretransmitted to different RxPs in a communication scenario using aplurality of RxPs, each of the PUCCHs may have a different TCI.

In a proposed method, in case that the last concatenation operation isnot defined, the required HARQ response bit string may be obtained. Whenall HARQ response bits are to be transmitted through one PUCCH or PUSCH,the required HARQ response bit strings may be obtained by performing thelast concatenation operation.

In a proposed method, the RxP order may be considered first, and thenthe order of sub-slots may be considered.

The terminal may generate the HARQ response codebook based on the 3GPPtechnical specification. The terminal may generate the HARQ responsecodebook by concatenating HARQ response bits according to the order ofreception timings of DL-DCIs, and generate an HARQ response bit stringby concatenating the HARQ response codebooks according to the order ofthe serving cells.

Since the PUCCHs corresponding to the HARQ response codebook may havedifferent TCIs, the HARQ response codebook may be transmitted ondifferent PUCCHs. The HARQ response codebooks may be generated byarranging the HARQ responses for the PDSCHs associated with the PUCCHsto be transmitted in the same sub-slot in a predefined order.

Thereafter, the terminal may generate HARQ response bit strings A byconcatenating the HARQ response codebooks in the order of the servingcells. Thereafter, the terminal may generate HARQ response bit strings Bby concatenating a plurality of HARQ response bit string A in the orderof CORESETs. Thereafter, the terminal may generate the HARQ response bitstring C by concatenating a plurality of HARQ response bit string B inthe order of the sub-slots. The HARQ response bit string C may betransmitted on a PUCCH or a PUSCH. This procedure may be performed basedon an algorithm defined in Table 7 below.

TABLE 7 For Sub-slot index     For CORESET index      For Serving cellindex         For scheduling DL-DCI order             Place the HARQ-ACKbit.         End scheduling DL-DCI index    End Serving cell index   End CORESET index End Sub-slot index

According to a proposed method, the last concatenation operation may beperformed in the order of the sub-slots. In order to quickly perform thefeedback operation, one HARQ response bit string may include HARQresponses to be transmitted to different RxPs. In order to support HARQresponse transmission for the URLLC PDSCH, the PUCCH may be transmittedon a sub-slot basis, and the HARQ response may be multiplexed in thePUSCH on a sub-slot basis.

In a proposed method, in case that the last concatenation operation isnot defined, the required HARQ response bit string may be transmittedthrough a PUCCH or a PUSCH on a sub-slot basis. When the delay timerequired for the HARQ response transmission procedure is satisfied, therequired HARQ response bit string may be obtained by performing the lastconcatenation operation.

Method of Generating CSI Reports Considering Different RxPs

The priority of RxP may be considered in the CSI reporting procedure.The CSI report may be triggered by DCI. Alternatively, the CSI reportmay be activated semi-persistent. Depending on the triggering method(e.g., activation method) of the CSI report, the CSI report may beclassified into a periodic CSI report, a semi-persistent CSI report, anda triggered CSI report. The transmission of the CSI report may beindicated by one transmission point (TxP) (e.g., base station), and theterminal may transmit the CSI report for one TxP to an RxP (e.g., basestation). When two or more DL carriers are configured and two or more DLcarriers are activated, the terminal may generate CSI reports for all orpart of DL BWPs. The CSI report may be mapped to a PUCCH or a PUSCH.

If there are many DL BWPs, all CSI reports may not be transmitted on aPUCCH or a PUSCH configured to the terminal. This is because theterminal cannot transmit the encoded CSI reports through the resourcesconfigured by the base station. In this case, the terminal may transmita portion of the CSI reports according to the priorities (e.g.,priorities defined in 3GPP technical specification) among all the CSIreports, and may not transmit the remaining CSI reports.

In order to consider the CSI reports for one or more TxPs and one ormore RxPs receiving the corresponding CSI reports, the priorities of theCSI reports defined in the 3GPP specification should be modified.

The base station may configure J PUCCH resources (e.g.,multi-CSI-PUCCH-Resource-List) in the terminal using higher layersignaling. J may be 1 or 2. When the terminal desires to transmit aplurality of CSI reports on a PUCCH configured in one slot, the terminalmay select one of a PUCCH resource 0 and a PUCCH resource J−1. In theprocedure of defining the PUCCH resource 0 and the PUCCH resource J−1,the base station may define the PUCCH resources such that the size ofthe PUCCH resource (e.g., the number of REs×code rate×modulation rate)increases. Accordingly, the PUCCH resource 1 may be greater than thePUCCH resource 0.

“CSI report(s)+other UCI (e.g., SR, HARQ response)+CRC” may berepresented in bits, and the corresponding bits may be encoded. When acodeword for the “CSI report(s)+other UCI (e.g., SR, HARQ response)+CRC”can be transmitted in the PUCCH resource 0, the terminal may transmitthe corresponding codeword using the PUCCH resource 0. When the codewordfor “CSI report(s)+other UCI (e.g., SR, HARQ response)+CRC” can betransmitted in the PUCCH resource 1, the terminal may transmit thecorresponding codeword using the PUCCH resource 1. When the codeword for“CSI report(s)+other UCI (e.g., SR, HARQ response)+CRC” cannot betransmitted in the PUCCH resources 0 and 1, the terminal may nottransmit some CSI report(s) from the entire CSI report(s).Alternatively, the terminal may transmit the CSI report(s) using aPUSCH. The CSI report not transmitted may be determined based on anequation defined in the 3GPP technical specification.

The priority of each of the CSI reports may be determined by thefollowing function. y may indicate a CSI reporting scheme (e.g.,periodic CSI reporting, semi-static CSI reporting, or triggered CSIreporting). k may indicate the type of CSI (e.g., L1-reference signalreceived power (L1-RSRP) or CSI other than L1-RSRP). c may be an indexof a serving cell. s may be an index of the CSI report.

The function for determining the priority of each of the CSI reports maybe defined as in Equation 9 below.pri(y,k,c,s)=2·k _(cells) ·M _(s) ·y+N _(cells) ·M _(s) ·k+·M _(s)·c+s  [Equation 9]

N_(cells) may indicate the maximum number of serving cells and may beconfigured by higher layer signaling. M_(s) may indicate the maximumnumber of CSI reports and may be configured by higher layer signaling.

When the CSI report is an aperiodic CSI report transmitted on a PUSCH, ymay be 0. When the CSI report is a semi-static CSI report transmitted ona PUSCH, y may be 1. When the CSI report is a semi-static CSI reporttransmitted on a PUCCH, y may be 2. When the CSI report is a periodicCSI report transmitted on a PUCCH, y may be 3. When the CSI reportincludes L1-RSRP, k may be 0. When the CSI report does not includeL1-RSRP, k may be 1. The terminal may determine that the smaller thepri(y, k, c, s), the higher the priority.

The base station may instruct the terminal to transmit the CSI report ona PUSCH. Here, y may be set to 0 or 1. In this case, transmission of twoCSI reports may collide with each other. When the terminal is instructedto transmit CSI reports on PUSCHs, the PUSCHs may overlap in the timedomain. In this case, the terminal may transmit a CSI report having ahigh priority (e.g., a CSI report having a low pri(y, k, c, s)) on aPUSCH associated with the corresponding CSI.

When a CSI report 1 is instructed to be transmitted on a PUCCH (e.g.,when y is 2 or 3), a CSI report 2 is instructed to be transmitted on aPUSCH (e.g., when y is 0 or 1), and the PUCCH on which the CSI report 1is to be transmitted overlaps with the PUSCH on which the CSI report 2is to be transmitted overlap in the time domain, the terminal may nottransmit a CSI report having a low priority (e.g., CSI report having ahigh pri(y, k, c, s)).

When all the CSI reports are transmitted on PUCCHs (e.g., when y is 2 or3), and the PUCCHs overlap in the time domain, the terminal may nottransmit a CSI report having a low priority CSI report (e.g., CSI reporthaving a high pri(y, k, c, s))), and multiplex CSI report(s) selectedaccording to the priorities. The multiplexed CSI report(s) may betransmitted on the PUCCH resource J−1.

In a proposed method, the priorities of the CSI reports for two or moretransmission reception points (TRPs) may be determined according to theorder (e.g., priorities) of the two or more TRPs. The priority of theCSI report for one TRP may be determined according to the 3GPP technicalspecification, and each of the TRPs may have a different offset. Thepriority of the CSI report for a TRP (e.g., TRP A) having a highpriority may be higher than the priority of the CSI report for a TRP(e.g., TRP B) having a low priority. Management of the TRP B may bedifficult because the priority of the most important CSI report amongall the CSI reports for the TRP B is also lower than the priorities ofany of CSI report for the TRP A.

In a proposed method, the CSI reports having the same priority may betransmitted in the order of the TRPs. The CSI reports having differentpriorities may be transmitted according to the priorities of the CSIreports regardless of the order of the TRPs. The priority of CSI reportmay be defined according to the 3GPP technical specification regardlessof the TRP indexes (e.g., TRP A, TRP B).

When the priorities of the CSI reports are determined according to afunction (e.g., equation 9), and the indices of the serving cellsassociated with the CSI reports are the same, the priorities of the CSIreports may be calculated regardless of the priorities of the TRPs.Since the priority of the TRP is independent of the priority of the CSIreport, if the indexes of the serving cells associated with the CSIreports are different, the priorities of the CSI reports may bedetermined based on the indexes of the serving cells regardless of thepriorities of the TRPs.

When the priorities of the CSI reports are different, the CSI reportsmay be transmitted according to the priorities of the TRPs. In the sameserving cell, the priority of channel quality indicator (CQI)/rankindicator (RI) report of each of the TRP A and B may be determined basedon the priority of the CQI/RI report, and the priority of L1-RSRP reportof each of the TRP A and B may be determined based on the priority ofthe L1-RSRP report. In the same serving cell, the relative prioritybetween the CQI/RI report of the TRP A and the L1-RSRP report of the TRPB may be determined based on a comparison result between the priority ofthe CQI/RI report and the priority of the L1-RSRP report regardless ofthe priorities of the TRP A and B. In contrast, in the same servingcell, when same CSI reports are performed by different TRPs (e.g., TRP Aand B), the priorities of the same CSI reports may be determined basedon the priorities of the different TRPs.

In a proposed method, the priorities of some CSI reports may bedetermined regardless of the priorities of the TRPs, and the prioritiesof the remaining CSI reports may be determined according to thepriorities of the TRPs. The CSI report may include a combination of oneor more among L1-RSRP, CQI, preceding matrix indicator (PMI), channelstate information-reference signal (CSI-RS) resource indicator (CRI),synchronization signal/physical broadcast channel (SS/PBCH) resourceblock indicator (SSBRI), layer indicator (LI), and RI. The type of CSIreport may vary according to information included in the CSI report. Thetype of CSI report may be indicated by higher layer signaling.

For example, the CSI report may be CQI, PMI, a combination of CRI, RI,PMI, and CQI, a combination of CRI, RI, LI, PMI, and CQI, a combinationof CRI, RI, and LI, and a combination of CRI, RI, and CQI, a combinationof CRI, RI, L1, and CQI, a combination of CRI and L1-RSRP, or acombination of SSBRI and L1-RSRP. Alternatively, the CSI report may notinclude any information.

In the conventional 3GPP technical specification, the type of CSI reportmay be classified into a CSI report including L1-RSRP and a CSI reportincluding information other than L1-RSRP. The priority of the CSI reportincluding L1-RSRP may be higher than the priority of the CSI reportincluding information other than the L1-RSRP. The priorities of CSIreports including information other than L1-RSRP may be the same.

All TRPs may have priorities. The priority of the TRP may correspond tothe priority of the CSI report. In the procedure for determining thepriorities for the ordered pairs (CSI report, TRP) of the same CSIreport trigger and the same serving cell index, the priority of the CSIreport including L1-RSRP may be higher than the priority of CSI reportincluding information other than L1-RSRP regardless of the priority ofthe TRP. In contrast, the priority of CSI reporting includinginformation other than L1-RSRP may be determined according to thepriority of the TRP.

Accordingly, a value of k may be newly introduced. For example, k mayreflect the priority of the TRP, and the priority of CSI report may bedetermined based on the new k. When two TRPs are present, (k=2) may beintroduced. (k=1) may be applied to the TRP having the highest priorityamong the TRPs, and (k=2) may be applied to the TRP having the lowestpriority among the TRPs. In this case, the CSI report may includeinformation other than L1-RSRP. (k=0) may be applied to the CSI reportincluding L1-RSRP regardless of the TRP. Since the value of k has one ofthree values, a value of y may be configured based on the value of k. Afunction for determining the priority of each of the CSI reports may bedefined as in Equation 10 below.pri(y,k,c,s)=3·N _(cells) ·M _(s) ·y+N _(cells) ·M _(s) ·k+·M _(s)·c+s  [Equation 10]

The above-described exemplary embodiment may be applied when thepriorities of m TRPs are discriminated. Here, m may be a natural number.For example, a function for determining the priority of each of the CSIreports may be defined as in Equation 11 below.pri(y,k,c,s)=m·N _(cells) ·M _(s) ·y+N _(cells) ·M _(s) ·k+·M _(s)·c+s  [Equation 11]

In a proposed method, when DL data channel candidates overlap in thetime domain in a generation procedure of an HARQ response codebookhaving a semi-static size, one DL data channel candidate may be selectedfrom among the DL data channel candidates.

When the size of the HARQ response codebook is semi-staticallydetermined, the terminal may derive the size of the HARQ responsecodebook from a feedback timing (e.g., slot offset or sub-slot offset)of the HARQ response and the DL data channel candidate (e.g., TDRAindex). In the communication system supporting the TDD scheme, the slotpattern may affect the size of the HARQ response codebook. The basestation may inform the terminal of at least one of the feedback timingof the HARQ response, a list (or a table) consisting of TDRA indexes,and the slot pattern using higher layer signaling. The number of HARQresponses generated within a unit time (e.g., one slot) may varydepending on the processing capability of the terminal. For example, theterminal may generate the HARQ response for one DL data channel or theHARQ responses for two or more DL data channels within a unit time(e.g., one slot).

The terminal may generate an HARQ response codebook for the HARQresponse for the DL control channel indicating the HARQ response for theDL data channel and the release of the SPS DL data channel (e.g.,semi-statically assigned DL data channel). When the DL control channelindicating the release of the SPS DL data channel is received, theterminal may generate the HARQ response based on a resource forreceiving the SPS DL data channel.

When the slot format is configured in the terminal by higher layersignaling, the terminal may not generate an HARQ response for the TDRAindex indicating the UL symbol. The terminal may generate HARQ responsesfor two or more DL data channels. In this case, an order may be assignedto valid DL data channel candidates (e.g., valid TDRA indexes) in a slot(or sub-slot). A reference symbol (e.g., symbol m) may be defined. Forexample, the most advanced symbol in the time domain among the lastsymbols of the valid DL data channel candidates may be configured as thereference symbol (e.g., symbol m).

When the first symbol (e.g., symbol S) of the valid DL data channelcandidate is equal to the symbol m, or when the first symbol (e.g.,symbol S) of the valid DL data channel candidate is located before thesymbol m, the order of HARQ response bits for the valid DL data channelcandidates may be early within the HARQ response codebook. When theorder is assigned to the valid DL data channel candidates, the orderedDL data channel candidates may be excluded in the later procedure ofdetermining the symbol S and the symbol m.

In this case, the base station may assign to the terminal two or more DLdata channels that overlap in the time domain but do not overlap in thefrequency domain. This operation may be necessary in the communicationsystem supporting the eMBB service and the URLLC service. The terminalmay multiplex an HARQ response of a DL data channel for supporting theeMBB service (e.g., high performance communication service) and an HARQresponse of a DL data channel for supporting the URLLC service (e.g.,service supporting an error rate of 1E-5) in the same HARQ responsecodebook.

In order to support a high level of URLLC service (e.g., servicesupporting an error rate of 1E-6), the base station may not need toassign two or more DL data channels to the terminal that overlap in thetime domain but do not overlap in the frequency domain. The reason isthat an HARQ response codebook in which an HARQ response for a DL datachannel for supporting the eMBB service (e.g., high performancecommunication service) is multiplexed is different from an HARQ responsecodebook in which an HARQ response for a DL data channel for supportingthe high level URLLC service.

Since the DL data channel is allocated to a small number of symbols,when assigning a new DL data channel for a new TB, the new DL datachannel may not overlap with the previous DL data channel in the timedomain. As the size of the HARQ response codebook is smaller, thereception quality of the UL control channel and/or the UL data channelmay increase. Therefore, the base station may preferably assign the DLdata channels so that the DL data channels do not overlap in the timedomain.

In a proposed method, when DL data channel candidates overlap in thetime domain, the terminal may select one DL data channel candidate amongthe overlapping DL data channel candidates, and consider the selected DLdata channel candidate as a valid DL data channel candidate. The validDL data channel candidate may not include UL symbols. The terminal maygenerate an HARQ response for the valid DL data channel candidate, andmay not generate an HARQ response for the remaining invalid DL datachannel candidate. The operation of selecting the DL data channelcandidates that do not overlap in the time domain may be added to thegeneration procedure of the HARQ response codebook.

Meanwhile, the procedure of excluding TDRA indexes may be applied invarious ways. For example, the proposed procedure may be applied first,and then the conventional procedure may be applied. Alternatively, theproposed procedure may be applied in the process of applying theconventional procedure. Alternatively, the conventional procedure may beapplied first, and the HARQ response bit (e.g., HARQ response value) maynot be mapped to some positions of the HARQ response codebook.Alternatively, a known value (e.g., NACK) may be mapped to somepositions of the HARQ response codebook.

According to the difference in the procedure, the position of the HARQresponse bit for the same TDRA index may be changed in the HARQ responsecodebook. The generation procedure of the HARQ response codebook may beshared between the base station and the terminal. Therefore, since thebase station knows the allocation order of the DL data channel, the basestation may know the position of the HARQ response bit for thecorresponding DL data channel in the HARQ response codebook.

The proposed procedure may be further applied to TDRA indexes configuredin the terminal. The terminal may derive simple TDRA indexes andgenerate an HARQ codebook for the simple TDRA indexes using theconventional procedure. The simple TDRA indexes may be the remainingTDRA indexes excluding TDRA indexes overlapping in the time domain amongall TDRA indexes.

FIG. 33 is a conceptual diagram illustrating a first exemplaryembodiment of a method for configuring a TDRA index in a communicationsystem.

Referring to FIG. 33 , TDRA index 0 may overlap TDRA index 1 in somesymbols of the time domain. In order to support a high level of URLLCservice, the base station may request the terminal to transmit an HARQresponse for TDRA index 0 or TDRA index 1. Although there are two TDRAindexes, the terminal may generate an HARQ response for one TDRA index(e.g., one DL data channel candidate). That is, the HARQ response forone DL data channel candidate may be included in an HARQ responsecodebook. The HARQ response for TDRA index 0 in the HARQ responsecodebook needs not be distinguished from the HARQ response for TDRAindex 1. The reason is that since the terminal follows the instructionof the base station, the base station may know which TDRA index the HARQresponse codebook received from the terminal includes.

FIG. 34A is a conceptual diagram illustrating a second exemplaryembodiment of a method of configuring a TDRA index in a communicationsystem, FIG. 34B is a conceptual diagram illustrating a third exemplaryembodiment of a method of configuring a TDRA index in a communicationsystem, and FIG. 34C is a conceptual diagram illustrating a fourthexemplary embodiment of a method of configuring a TDRA index in acommunication system.

Referring to FIGS. 34A to 34C, TDRA index 2 may overlap TDRA index 0 andTDRA index 1 in some symbols of the time domain. According to theconventional procedure, in the exemplary embodiment shown in FIG. 34A,the order of HARQ responses in the HARQ response codebook may be “HARQresponse for TDRA index 2→HARQ response for TDRA index 0→HARQ responsefor TDRA index 1”. In the exemplary embodiment shown in FIG. 34B, theorder of HARQ responses in the HARQ response codebook may be “HARQresponse for TDRA index 0→HARQ response for TDRA index 2→HARQ responsefor TDRA index 1”. In the exemplary embodiment shown in FIG. 34C, theorder of HARQ responses in the HARQ response codebook may be “HARQresponse for TDRA index 0→HARQ response for TDRA index 2→HARQ responsefor TDRA index 1”.

According to a proposed method, when the assignment information of TDRAindex 2 is obtained, the terminal may expect not to obtain theassignment information of TDRA index 0 and the assignment information ofTDRA index 1. When the assignment information of TDRA index 0 and/or theassignment information of TDRA index 1 is obtained, the terminal mayexpect not to obtain the assignment information of TDRA index 2. In thiscase, the terminal may generate an HARQ response codebook for two TDRAindexes.

When one TDRA index corresponds to one HARQ response bit (or HARQresponse bit pair), the HARQ response may be represented by two HARQresponse bits (or two pairs of HARQ response bits). The first HARQresponse bit (or the first HARQ response bit pair) may correspond toTDRA index 0 or TDRA index 2. The second HARQ response bit (or secondHARQ response bit pair) may correspond to TDRA index 1 or TDRA index 2.The HARQ response bit for TDRA index 2 may belong to one of the firstHARQ response bit (or the first HARQ response bit pair) or the secondHARQ response bit (or the second HARQ response bit pair).

The order of HARQ response bits in the HARQ response codebook generatedby the terminal may be “HARQ response bit for TDRA index 0→HARQ responsebit for TDRA index 1”. When TDRA index 0 is assigned, the terminal maymap the HARQ response for TDRA index 0 to the first position in the HARQresponse codebook. When TDRA index 1 is assigned, the terminal may mapthe HARQ response for TDRA index 1 to the second position in the HARQresponse codebook. When TDRA index 2 is assigned, the terminal may mapthe HARQ response for TDRA index 2 to the first position or the secondposition in the HARQ response codebook. When the HARQ response codebookdoes not include an HARQ response for the TDRA index, the correspondingHARQ response codebook may be regarded as NACK.

In a proposed method, the terminal may not transmit UCI according to anindication of a DL control channel.

The terminal may generate UCI based on a DL control channel (e.g., DCI)received from the base station. In particular, the terminal may generatean HARQ response for the DL data channel scheduled by the DL controlchannel. The DL control channel may include radio resource informationof the DL data channel and radio resource information of the UL controlchannel. According to the conventional method, the terminal may generatean HARQ response for the DL data channel scheduled by the DL controlchannel, and may transmit a UL control channel or UL data channelincluding the HARQ response using a radio resource configured by thebase station.

In a communication system supporting minimum transmission delay andshort deadline of data, the base station may not be able to decode a ULcontrol channel including an HARQ response. For example, when theterminal fails to decode a DL data channel assigned by the base stationand transmits a NACK, the base station should reassign the DL datachannel. When the remaining time for the TB is small, the base stationmay not receive the HARQ response from the terminal. In this case, theterminal may preferably not transmit the HARQ response to the basestation. Since the terminal cannot know the remaining time for the TB,the terminal may determine whether to feedback the HARQ responseaccording to signaling of the base station. The base station may informthe terminal whether to feedback the HARQ response by using an explicitsignaling method or an implicit signaling method.

When an implicit signaling method is used, the base station may informthe terminal whether or not to feed back the HARQ response by using acombination of values of fields included in the DCI. The terminal mayreceive the DCI from the base station, and may determine that feedbackof the HARQ response is requested when the combination of the values ofthe fields included in the DCI has a first value. The terminal maydetermine that feedback of the HARQ response is not requested when thecombination of the values of the fields included in the DCI has a secondvalue. The combination of the values of the fields included in the DCImay indicate an invalid scheduling or a valid scheduling to theterminal.

The above-described operation may be applied not only when the DL datachannel is dynamically scheduled but also when the DL data channel issemi-statically scheduled. When the DL data channel is configured by theSPS and the DCI indicates activation of the DL data channel configuredby the SPS, the terminal may determine whether to feedback the HARQresponse based on the corresponding DCI.

Meanwhile, the terminal may transmit HARQ responses for two types of DLdata channels (e.g., DL data channels A and B) on the same UL controlchannel. Feedback of the HARQ response for the DL data channel A may beneeded, but feedback of the HARQ response for the DL data channel B maynot be needed. The terminal may generate an HARQ response codebookincluding at least the HARQ response for the DL data channel A. The sizeof the HARQ response codebook may be determined in consideration of theHARQ response for at least the DL data channel A.

When the size of the HARQ response codebook is semi-statically indicated(e.g., type 1 in the 3GPP technical specification), the size of the HARQresponse codebook may be determined by reflecting both the number of theDL data channels A and the number of the DL data channels B. Theterminal may map an HARQ response bit for the DL data channel A to theHARQ response codebook, and may map an already-known value (e.g., NACK)as an HARQ response bit for the DL data channel B to the HARQ responsecodebook.

When the size of the HARQ response codebook is dynamically indicated(e.g., type 2 in the 3GPP technical specification), the size of the HARQresponse codebook may be determined by reflecting a DAI for the DL datachannel A. The DAI may be obtained from DL control channel(s), and theterminal may not increase the DAI when receiving a DCI for the DL datachannel B.

When one or more of the methods proposed below are applied, the terminalmay not feed back an HARQ response. In the proposed methods, the basestation may inform the terminal whether or not to feed back the HARQresponse by using an explicit signaling method or an implicit signalingmethod. The terminal may not feedback the HARQ response according to theindication of the base station.

The DCI (e.g., DL-DCI) transmitted on the DL control channel may includeradio resource information of the DL data channel and characteristicinformation of the TB. For example, the DCI may include a new dataindicator (NDI) field, an HARQ process identification information, a CBGtransmission index, a CBG flush index, a DAI field, a resource index ofa UL control channel (PUCCH resource index), and the like.

In a proposed method, the value of the NDI field may be changed, and thevalue of the DAI field (e.g., counter DAI and/or total DAI) may not bechanged.

In the conventional method, a toggled NDI may indicate that the TBallocated by the DCI is a new TB. The terminal may determine that thesize of the HARQ response codebook remains the same as before based onthe value of the DAI field. That is, the terminal may determine thatthere is no new UCI, and thus may not generate an HARQ response for thenew TB. Alternatively, even when generating the HARQ response for thenew TB, the terminal may not include the corresponding HARQ response inthe HARQ response codebook.

In a proposed explicit signaling method, the base station may explicitlyinform the terminal whether or not to feed back the HARQ response byusing a specific field included in the DCI. For example, when a specificfield included in the DCI has a first value, the terminal may feedbackthe HARQ response to the base station. When the specific field includedin the DCI has a second value, the terminal may not feedback the HARQresponse to the base station.

In the following exemplary embodiments, the fact that the HARQ responsecodebook does not include HARQ response bits means that the terminalmaps an already-known value (e.g., NACK) to the corresponding position(e.g., the position corresponding to a HARQ process) in the HARQresponse codebook or that the HARQ response bit is missing in the HARQresponse codebook. For example, when the size of the HARQ responsecodebook is semi-statically determined, the terminal may map analready-known value to the corresponding position in the HARQ responsecodebook. When the size of the HARQ response codebook is dynamicallychanged, the terminal may not map the HARQ response bit to the HARQresponse codebook. That is, the HARQ response bit may be missing fromthe HARQ response codebook.

In a proposed implicit signaling method, when the terminal knows thatthe TB is a TB for low latency communication (hereinafter, referred toas a ‘low latency TB’), the base station may configure a redundancyversion (RV) for the low latency TB to a specific value, and may informthe terminal of the RV configured to the specific value. When the RV isconfigured to the specific value, the terminal may not transmit the ULcontrol channel corresponding to the HARQ response (e.g., UCI)one-to-one with respect to the low latency TB. Alternatively, theterminal may not map the HARQ response (e.g., UCI) for the low latencyTB to the HARQ response codebook.

The above operation may be applied to a TB assigned by a DCI and a TBassigned by SPS. When the TB is assigned by semi-static scheduling(e.g., SPS), the terminal may determine whether the TB is a low latencyTB based on a logical channel index. When TB is assigned by dynamicscheduling (e.g., DCI), the terminal may identify whether the TB is alow latency TB based on a search space (e.g., specific search spaceconfigured by higher layer signaling) of a DL control channel (e.g.,DCI) or an RNTI (e.g., MCS-C-RNTI or separate RNTI) used for scramblinga CRC of the DL control channel (e.g., CRC of the DCI).

When a DL data channel is assigned by a DL control channel, the basestation may explicitly inform the terminal of an RV for a codeword. TheRV of the initially transmitted TB may be configured to a specificvalue. According to a proposed method, the terminal may know in advancea sequence of specific values of the RV. Therefore, when the basestation informs the terminal of the RV set to a specific value, theterminal may determine that the corresponding TB is aninitially-transmitted TB or a retransmitted TB based on the RV. Theterminal may generate an HARQ response (e.g., UCI) by decoding the TBand may not map the HARQ response to an HARQ response codebook.

For example, the value of RV may be 0, 1, 2, or 3. When the RV is set to1 or 3, the HARQ response for the TB may not be included in the HARQresponse codebook. When the RV is set to 0 or 2, the HARQ response forthe TB may be included in the HARQ response codebook. These operationsmay be indicated by higher layer signaling. Alternatively, theseoperations may be predefined in the 3GPP technical specification. Theterminal does not know whether the TB is an initially-transmitted TB ora retransmitted TB, but may determine whether to feedback the HARQresponse to the TB based on the RV.

For example, when the terminal knows that RV is indicated by a sequenceand the RV is represented in the order of (0, 2, 3, 1), if the RV is setto 0, the HARQ response for TB may be included in the HARQ responsecodebook. If the RV is set to the remaining value (e.g., 2, 3, or 1),the HARQ response may not be included in the HARQ response codebook.These operations may be indicated by higher layer signaling.Alternatively, these operations may be predefined in the 3GPP technicalspecification. If the RV is set to 0, the terminal may determine thatthe RV 0 is reassigned by the base station even when the TB is aninitially-transmitted TB or a retransmitted TB. Accordingly, theterminal may generate the HARQ response by decoding the TB, and may mapthe HARQ response to the HARQ response codebook.

For example, if the RV is set to a specific value (e.g., 1), theterminal may not feed back the HARQ response for the TB. That is, theHARQ response may not be mapped to the HARQ response codebook.Alternatively, if the RV is set to another value (e.g., 0, 2, or 3), theterminal may feed back the HARQ response for the TB. That is, the HARQresponse may be mapped to the HARQ response codebook.

In a proposed implicit signaling method, when the terminal knows thatthe TB is a low-latency TB, and a NDI included in the DCI scheduling theTB is maintained as the previous value, the terminal may transmit a ULcontrol channel one-to-one corresponding to the HARQ response (e.g.,UCI) for the corresponding TB. The HARQ response for that TB may not bemapped to the HARQ response codebook.

The method described above may be applied when the TB is dynamicallyscheduled or when the TB is semi-statically scheduled. The terminal mayknow that the TB is a low latency TB based on the above-describedmethods. When the above-described method is applied, the terminal maydetermine that the TB is a retransmitted TB when the NDI included in theDCI is maintained, and thus may not feed back the HARQ response.

In a proposed implicit signaling method, when the feedback timing of theHARQ response configured by the base station is smaller than a specificvalue, and the NDI included in the DCI is maintained as the previousvalue, the terminal may transmit a UL control channel which correspondsone-to-one to the HARQ response (e.g., UCI) for the corresponding TB.Alternatively, the HARQ response for the corresponding TB may not bemapped to the HARQ response codebook.

The base station may set a specific value in consideration of theprocessing capability of the terminal, and may inform the terminal ofthe specific value through higher layer signaling. Alternatively, if thespecific value is set to the minimum feedback time value according tothe processing capability of the terminal, higher layer signaling forinforming the specific value may not be performed. When the NDI includedin the DCI is set to a new value, the terminal may determine that thecorresponding TB is a new TB, and may feed back an HARQ response for thenew TB. The base station may not instruct a fast feedback operationbeyond the processing capability of the terminal.

The terminal may receive a DL data channel in a minimum time intervalrequired according to the processing capability, and generate an HARQresponse for a TB (e.g., DL data channel) by decoding the DL datachannel. The terminal may inform the base station of its processingcapability using higher layer signaling. If the specific value is theminimum feedback time required by the terminal (e.g., when the feedbacktime of the HARQ response indicated by the DCI scheduling the TB exceedsthe processing capacity of the terminal), the terminal may not transmita UL control channel which corresponds one-to-one to the HARQ response(e.g., UCI) for the corresponding TB. The HARQ response may not bemapped to the HARQ response codebook.

In a proposed method, when a field included in the DCI indicates thefeedback time of the HARQ response set to a specific value, and the NDIincluded in the DCI is maintained as the previous value, the terminalmay not transmit a UL control channel which corresponds one-to-one tothe HARQ response (e.g., UCI) for the corresponding TB. The HARQresponse may not be mapped to the HARQ response codebook.

According to the conventional method, the base station may configuretime resources of UL control channels using higher layer signaling, andmay transmit a DCI indicating one time resource among the time resourcesconfigured by higher layer signaling. The terminal may transmit an HARQresponse for a DL data channel through a UL control channel indicated byhigher layer signaling and a DCI. In a proposed method, a specific valueamong the values configured by higher layer signaling may indicate thatthe HARQ response (e.g., UCI) is not included in an HARQ responsecodebook.

A slot for feeding back the HARQ response may be indicated by the DCI.For example, ‘PDSCH-to-HARQ_feedback timing indicator’ defined in Table8 below may be included in the DCI and may indicate the slot for feedingback the HARQ response.

TABLE 8 PDSCH-to-HARQ_feedback timing indicator 1 bit 2 bits 3 bitsNumber of slots ^(k) ‘0’ ‘00’ ‘000’  l^(st) value provided bydl-DataToUL-ACK ‘1’ ‘01’ ‘001’ 2^(nd) value provided by dl-DataToUL-ACK‘10’ ‘010’ 3^(rd) value provided by dl-DataToUL-ACK ‘11’ ‘011’ 4^(th)value provided by dl-DataToUL-ACK ‘100’ 5^(th) value provided bydl-DataToUL-ACK ‘101’ 6^(th) value provided by dl-DataToUL-ACK ‘110’7^(th) value provided by dl-DataToUL-ACK ‘111’ 8^(th) value provided bydl-DataToUL-ACK

Here, ‘dl-DataToUL-ACK’ may be configured in the terminal using higherlayer signaling. The dl-DataToUL-ACK may have a value between 0 and 15,and the number of dl-DataToUL-ACKs configured in the terminal may be upto eight. In a proposed method, the dl-DataToUL-ACK may be set to avalue other than 0 to 15. The dl-DataToUL-ACK having the value otherthan 0 to 15 may be configured in the terminal using higher layersignaling. When ‘PDSCH-to-HARQ_feedback timing indicator’ included inthe DCI indicates that dl-DataToUL-ACK having the value other than 0 to15, the terminal may not map an HARQ response for a DL data channelscheduled by the DCI to an HARQ response codebook. For example, whendl-DataToUL-ACK has the value other than 0 to 15, a value defined in the3GPP technical specification, or a value configured by the higher layersignaling, the terminal may not map any HARQ-ACK bit for the TB.

In a proposed method, when a PRI included in the DCI is set to aspecific value, and a NDI included in the DCI is maintained as theprevious value, the terminal transmits an HARQ response (e.g., for a DLdata channel scheduled by the corresponding DCI). UCI) may not transmita UL control channel which corresponds one-to-one to the HARQ response(e.g., UCI) for the corresponding TB. The HARQ response may not bemapped to the HARQ response codebook.

The base station may configure a set of UL control channels to theterminal using higher layer signaling. The terminal may identify a radioresource of a UL control channel based on a specific field included inthe DL control channel (e.g., DCI) or an index of a CCE to which the DLcontrol channel is mapped. When the radio resource indicated by the DCIis a specific radio resource among the radio resources of UL controlchannels configured by higher layer signaling, the terminal maydetermine that the feedback of the HARQ response is not requested.

In a proposed method, the terminal may transmit a UL control channelincluding the HARQ response when the HARQ response for the DL datachannel is an NACK.

Meanwhile, when a transmission target error rate of the DL data channelis low, a difference between an occurrence rate of ACK and an occurrencerate of NACK may increase. When the transmission target error rate is1E-1, an expected occurrence ratio of ACK and NACK may be 9:1. When thetransmission target error rate is 1E-5, the expected occurrence ratio ofACK and NACK may be 99999:1. Instead of allocating the radio resourcefor the HARQ response, if the feedback operation of the HARQ response isperformed through a separate procedure when the HARQ response is NACK,the usage of the UL radio resource may be reduced.

In a proposed method, the terminal may transmit a UL control channelincluding the corresponding HARQ response when the HARQ response is aNACK. The radio resource of the UL control channel may be indicated bythe information included in the DCI scheduling the TB associated withthe corresponding UL control channel. When the transmission target errorrate of the DL data channel is low, it is preferable that the basestation does not allocate TB to two or more terminals. The terminal mayreceive one TB from the base station and generate an HARQ response forthe received TB.

In a proposed method, one radio resource for the feedback of the HARQresponse may be shared by a plurality of terminals, and the terminal maytransmit its identification information to the base station using theshared radio resource when the HARQ response is a NACK. Here, theidentification information may be an RNTI of the terminal or information(e.g., PDSCH DM-RS ID) obtained from the DCI.

When the DL data channel is semi-statically scheduled and a feedbackperiodicity of the HARQ response configured in the terminal is short(e.g., when the feedback periodicity is a few slots or a few symbols),the size of the UL control channel required to transmit the HARQresponse for each DL data channel may be large. In this case, theterminal may transmit the UL control channel including a NACK only whenthe NACK occurs. Accordingly, the size of the required UL controlchannel may be reduced, and power consumption may also be reduced at theterminal.

Since the results of the decoding operation on the DL data channel aremostly ACK, the terminal may not transmit a UL control channel in mostcases. Accordingly, if the base station does not receive an HARQresponse (e.g., UL control channel) from the terminal, the base stationmay determine that the DL data channel associated with the correspondingHARQ response has been successfully received at the terminal. When thebase station receives an HARQ response (e.g., UL control channel) fromthe terminal, the base station may regard the corresponding HARQresponse as NACK.

In case of feeding back an HARQ response for an SPS PDSCH, the terminalmay use a format of UL control channel for transmitting one UCI bit(e.g., one HARQ response bit). Since the UL control channel isconfigured with a specific sequence, the base station may consider thatthe HARQ response is NACK when a specific sequence is detected in the ULcontrol channel. The base station may consider the HARQ response as ACKif the specific sequence is not detected in the UL control channel.

The terminal may map an HARQ response (e.g., a large amount of UCI) forthe dynamically-assigned DL data channel and an HARQ response for asemi-statically assigned DL data channel to the same UL control channel.In this case, when the size of the HARQ response codebook is dynamicallydetermined, an HARQ response codebook may not include the HARQ responsefor the SPS PDSCH. If the size of the HARQ response codebook isdetermined semi-statically, the HARQ response codebook may include theHARQ response for the SPS PDSCH.

In a proposed method, feedback of HARQ response(s) for some DL datachannel(s) of a plurality of DL data channels activated amongsemi-statically assigned DL data channels may be omitted.

When the base station periodically transmits a DL data channel to theterminal, the PDSCH may be transmitted through semi-static resourceallocation, but transmission of a PDCCH may be omitted. This operationmay be introduced for periodic transmission of small traffic (e.g.,voice over internet protocol (VoIP) traffic) and for reducing CCEoverheads. The URLLC traffic in the NR communication system may have asmall size similarly to the VoIP traffic. In addition, the URLLC trafficmay be transmitted periodically similarly to the VoIP traffic.Transmission reliability of the URLLC traffic may be higher thantransmission reliability of the VoIP traffic. Since a low code rate isapplied to a TB having a small size, the number of REs to which the DLdata channel is mapped in the resource grid may not be small.

Alternatively, the URLLC traffic may not be transmitted periodically.For example, although the URLLC traffic may occur periodically onaverage, but may occur randomly instantaneously. In this case, the URLLCtraffic may have a random offset, and an average periodicity of theURLLC traffic may be semi-static. The random offset may be referred toas a jitter, and the average periodicity may be referred to as a cycletime.

For example, according to TS 22.804, the cycle time of a mobile controlpanel with safety function may be 4 millisecond (ms) or more and 8 ms orless, and the mobile control panel with safety function have a jitterless than 50%. The data size is 40 bytes or more and 250 bytes or less.According to TS 22.804, a cycle time of a mobile robot may be configuredvariously. The cycle time required for accurate motion control may be 1ms. The cycle time required for typical mobile robot operation may beless than 500 ms and jitter therefor may be less than 50%. According toTS 22.804, a cycle time of process automation may be within 10 ms and ajitter therefor may be less than 10%.

The base station may configure a DL SPS in the terminal using higherlayer signaling (e.g., an RRC message). The RRC message for configuringthe DL SPS may include information (e.g., periodicity, subframe offset)indicating time resources in which the SPS PDSCH is allocated.

In a proposed method, the periodicity of the SPS PDSCH may be configuredin units of symbols or slots.

When the periodicity of the SPS PDSCH is configured as a physical time(e.g., ms), the periodicity of the SPS PDSCH may be configuredregardless of a subcarrier spacing of the corresponding DL BWP. In orderto support transmission of various traffic on the SPS PDSCH, it may bepreferable that the periodicity of the SPS PDSCH is configured as arelative time. In a proposed method, the periodicity of the SPS PDSCHmay be configured in units of slots or symbols.

According to the conventional method, the periodicity of the SPS PDSCHmay be set to one of 10 ms, 20 ms, 32 ms, 40 ms, 64 ms, 80 ms, 128 ms,160 ms, 320 ms, and 640 ms. In this case, traffic having a transmissionperiodicity shorter than a radio frame (e.g., 5 ms) may not betransmitted through the SPS PDSCH. In order to solve this problem, theperiodicity of the SPS PDSCH may be preferably configured in units ofslots or symbols. In this case, since the periodicity of the SPS PDSCHis determined based on a subcarrier spacing, it may be interpreted thatsubdivided periodicities of the SPS PDSCH are introduced. For example,if the periodicity of the SPS PDSCH is interpreted as 10 ms (e.g., 10slots) at a subcarrier spacing of 15 kHz, the periodicity of the SPSPDSCH may be interpreted as 5 ms at a subcarrier spacing of 30 kHz andinterpreted as 2.5 ms at a subcarrier spacing of 60 kHz.

Meanwhile, a periodicity of a UL SPS assigned by a UL configured grantmay be defined in units of symbols or slots. A value and a unit relatedto the periodicity of the UL SPS may be equally applied to theperiodicity of the DL SPS. The periodicity of the UL SPS or DL SPS maybe 2 symbols, 6 symbols, 7 symbols, 1 slot, 2 slots, 4 slots, 5 slots, 8slots, 10 slots, 16 slots, 20 slots, 128 slots, 160 slots, 256 slots,320 slots, 512 slots, 640 slots, 1280 slots, or 2560 slots. When theextended CP is used, one slot may include 12 symbols. When the normal CPis used, one slot may include 14 symbols.

In a proposed method, each of a DCI indicating activation of the SPSPDSCH, a DCI indicating activation of the SPS PUSCH, a DCI indicatingrelease of the activated SPS PDSCH, and a DCI indicating release of theactivated SPS PUSCH may include an index and/or a bitmap. Each of theindex and bitmap included in the DCI may indicate a combination of oneor more SPS PDSCHs (or a combination of one or more SPS PUSCHs).

The base station may configure a plurality of DL SPSs for thecorresponding DL BWP to the terminal using higher layer signaling (e.g.,RRC message), and may transmit to the terminal a DL-DCI to activate ordeactivate some DL SPS(s) among the plurality of DL SPSs configured byhigher layer signaling. The DL-DCI (e.g., CRC of the DL-DCI) may bescrambled with a specific RNTI. The terminal may determine that the SPSPDSCH indicated by the DL-DCI is activated or deactivated.

These operations may equally apply to the UL SPS. The base station mayconfigure a plurality of UL SPSs for a UL BWP to the terminal usinghigher layer signaling (e.g., RRC message), and may transmit to theterminal a UL-DCI activating or deactivating some UL SPS(s) among theplurality of UL SPSs configured by higher layer signaling. The UL-DCI(e.g., CRC of the UL-DCI) may be scrambled with a specific RNTI. Theterminal may determine that a SPS PUSCH indicated by the UL-DCI isactivated or deactivated.

A plurality of DL SPSs may be configured in a DL BWP, and activation ordeactivation of the DL SPS may be indicated by a DL-DCI (e.g., DCIformat 1_0, DCI format 1_1, or DCI format 1_2). The DL-DCI may indicatea unique DL SPS. Therefore, a separate index for indicating the DL SPSmay not be needed. When two or more DL SPSs are activated in the DL BWP,the DL-DCI may include a field indicating the DL SPSs to be activated.That is, a specific field included in the DL-DCI may indicate two ormore DL SPSs.

In a proposed method, the specific field included in the DL-DCI mayindicate one or more DL SPS indexes. If the specific field of the DL-DCIincludes one or more DL SPS indexes, the length of the specific field ofthe DL-DCI may depend on the number of bits needed to represent the DLSPS indexes.

The base station may identify the size of the specific field (e.g., thespecific field included in the DCI) indicating one or more DL SPSindexes based on the number of DL SPSs configured in the DL BWP. Thebase station may inform the terminal of information instructing toreceive the DL-DCI including the specific field indicating one or moreDL SPS indexes by using higher layer signaling (e.g., RRC message). Inthis case, the RRC message may include DL-DCI related information (e.g.,the size of the specific field).

In a proposed method, the specific field of the DL-DCI may include abitmap indicating one or more DL SPS indexes. The length of the bitmapmay be determined based on the number of DL SPSs configured in the DLBWP. A bit set to 0 in the bitmap may indicate that the corresponding DLSPS is deactivated, and a bit set to 1 in the bitmap may indicate thatthe corresponding DL SPS is activated. The base station may inform theterminal of information instructing to receive the DL-DCI including thebitmap indicating one or more DL SPS indexes using higher layersignaling (e.g., RRC message). In this case, the RRC message may includeDL-DCI related information (e.g., the length of the bitmap).

In a proposed method, the DL-DCI may activate or deactivate one or moreDL SPSs. To support this operation, one DL SPS index or one bit includedin the bitmap may indicate two or more DL SPSs. A set of one or more DLSPSs may be referred to as a DL SPS set. An SPS PDSCH periodicity, aresource index of a UL control channel used for HARQ transmission, anMCS table, and the number of HARQ processes for each of DL SPSsbelonging to the same DL SPS set may be configured identically orindependently. The DL SPSs belonging to the same DL SPS set may beactivated or deactivated by one DL-DCI.

Meanwhile, the DL SPS activated by the DL-DCI may be applied to anotherDL BWP. For example, when a DL SPS is configured in a DL BWP 1, a DL SPSindicated by a DL SPS index or a bitmap included in the DL-DCI may beapplied to a DL BWP 2. The DL SPS(s) indicated by the DL-DCI mayindicate the DL SPS(s) that are currently active in the DL BWP 1 and/orthe changed DL BWP 2. In this case, the terminal may determine that theDL SPS(s) are activated or deactivated in the DL BWP 2. The DL SPS indexor bitmap included in the DL-DCI of the DL BWP 1 may be changed.

For example, when the length of a specific field in the DL BWP 1 (i.e.,a specific field included in the DL-DCI) is shorter than the length of aspecific field in the DL BWP 2, in order to match the length of thespecific field of the DL BWP 1 to be equal to the length of the specificfield of the DL BWP 2, a most significant bit (MSB) or a leastsignificant bit (LSB) may be added to a value of the specific field inthe DL BWP 1. Each of the MSB and LSB may be 0 or 1. The terminal maydetermine that the DL SPS(s) indicated by the DL-DCI of the DL BWP 1 areactivated in the DL BWP 2. For example, when the length of the specificfield in the DL BWP 1 (i.e., the specific field included in the DL-DCI)is longer than the length of the specific field in the DL BWP 2, inorder to match the length of the specific field of the DL BWP 1 to beequal to the length of the specific field of the DL BWP 2, the MSB orLSB may be deleted from the value of the specific field in the DL BWP 1.The terminal may determine that the DL SPS(s) indicated by the DL-DCI ofthe DL BWP 1 are activated in the DL BWP 2.

These operations may be applied to a UL SPS (e.g., configured grant Type2 of the NR communication system). A CRC of a UL grant (e.g., DCI format0_0, DCI format 0_1, or DCI format 0_2) may be scrambled with an RNTI(e.g., CS-RNTI) for supporting the UL SPS. In this case, a specificfield of the UL-DCI may indicate one or more UL SPS indexes. When thespecific field of the UL-DCI indicates two or more UL SPS indices, thespecific field may be represented by a bitmap. The UL SPS index(es) orbitmap included in the UL-DCI may indicate one or more UL SPSs among aplurality of UL SPSs configured by higher layer signaling.

The base station may identify the size of the specific field (e.g.,bitmap) included in the UL-DCI based on the number of UL SPSs configuredin the terminal. The base station may configure information indicatingthe size of the specific field (e.g., bitmap) of the UL-DCI to theterminal using higher layer signaling. This configuration operation maybe performed in consideration of the number of SPS PUSCHs configured inthe corresponding carrier. When the size of the specific field (e.g.,the specific field included in the UL-DCI) in the UL BWP 1 is differentfrom the size of the specific field in the UL BWP 2, an MSB or LSB maybe added to the specific field of the UL-DCI. Alternatively, the MSB orLSB may be deleted from the value of the specific field of the UL-DCI.

In a proposed method, a HARQ process identifier (HPID) of the SPS PDSCHmay be determined based on a symbol used for initial transmission.

According to the conventional method, an HPID for the SPS PDSCH may bedetermined based on a slot or a subframe to which a time resource of theSPS PDSCH belongs. Since one DL SPS is activated in the DL BWP, the HPIDmay be explicitly indicated by the DL-DCI (e.g., DCI format 1_0, DCIformat 1_1, or DCI format 1_2) so that the HPIDs of dynamically assignedPDSCHs do not overlap.

In a proposed method, a reference time for deriving the HPID may be thefirst symbol of the SPS PDSCH. The first symbol of the SPS PDSCH may bederived based on the first radio frame (e.g., the first system framenumber (SFN)), the current radio frame (e.g., the current SFN), and anindex of a symbol (e.g., symbol number) located in the current slot(e.g., slot number).

For example, the HPID may be determined based on“[floor(CURRENT_symbol/periodicity)] modulo nrofHARQ-Processes”. Here,CURRENT_symbol may be a result of(SFN×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+slot number in theframe×numberOfSymbolsPerSlot+symbol number in the slot). Here,numberOfSlotsPerFrame may indicate the number of slots included in theradio frame. Here, numberOfSymbolsPerSlot may indicate the number ofsymbols included in the slot. Each of numberOfSlotsPerFrame andnumberOfSymbolsPerSlot may be a constant defined in the 3GPP technicalspecification. Here, periodicity may indicate the periodicity of the DLSPS. Here, nrofHARQ-Process may indicate the number of HARQ processes.The base station may inform the terminal of periodicity andnrofHARQ-Process using higher layer signaling (e.g., RRC message).

When two or more DL SPSs are activated, the HPIDs for the two or more DLSPSs may be the same even if the reference times for deriving the HPIDsare different. In this case, the HARQ process performed by the terminalmay not be accurately defined. When two or more DL SPSs having the sameHPID are received, the terminal may regard the corresponding HPID as theHPID for one DL SPS.

In order to solve this problem, when the HPIDs of the DL SPSs collide,an offset of the HPID may be applied in one DL SPS. Therefore, the HPIDsof the DL SPSs may always have different values. This operation may beapplied when two DL SPSs have the same HPID. The periodicity of the DLSPS for supporting the URLLC service may be a small number of symbols.Therefore, there may be three or more DL SPSs having the same HPID. Whenthe HPID offset is applied, the HPID of the DL SPS according to the HPIDoffset may be the same as the HPID of another DL SPS. Therefore, whenthe HPID offset is applied, another collision problem may be caused.

In a proposed method, since the base station knows the DL SPSs havingthe same HPID, the base station may perform a dynamic schedulingoperation for the DL SPS which is lately mapped to the HPID among thecorresponding DL SPSs. That is, the corresponding DL SPS may be adynamic scheduling operation rather than a semi-static schedulingoperation.

The base station may dynamically assign a PDSCH in a time resourceoverlapping a SPS PDSCH in the time domain. When a semi-staticallyassigned PDSCH in the time domain overlaps a dynamically assigned PDSCH,the terminal may expect to receive DL data through the dynamicallyassigned PDSCH. This operation may be a method of considering the HPIDas an HPID for an early-received SPS PDSCH.

In a proposed method, the HPID may be considered as an HPID for alately-received SPS PDSCH. The terminal may store soft bits of the lastreceived SPS PDSCH in a soft buffer position corresponding to the HPIDfor the previously received SPS PDSCH.

When two or more SPS PDSCHs are received at the terminal at similartimings, a time budget for a retransmission procedure of the SPS PDSCHreceived earlier at the terminal may be present at the base station. Ifthe SPS PDSCH transmission satisfies the URLLC requirement, the basestation may proceed quickly with the retransmission procedure.Therefore, it may be preferable to utilize the corresponding HPID forthe SPS PDSCH received later at the terminal.

In a proposed method, the terminal may interpret the HPID for the SPSPDSCH having a high priority based on the priority of the traffic (e.g.,URLLC traffic having a high priority or eMBB traffic having a lowpriority), which is implicitly or explicitly indicated by the DL-DCIactivating the DL SPS.

When the HPID for the SPS PDSCH supporting the URLLC is the same as theHPID for the SPS PDSCH supporting the eMBB, the terminal may not receivethe SPS PDSCH supporting the eMBB. In this case, the terminal may notfeed back an HARQ response (e.g., HARQ response for the SPS PDSCHsupporting the eMBB). Alternatively, the terminal may feed back a NACK.

These operations may be applied to UL SPS. When two or more SPS PUSCHshave the same HPID, three or more SPS PUSCHs may have the same HPID evenif an HPID offset is applied. Alternatively, the HPID of the SPS PUSCHto which the HPID offset is applied may collide with the HPID foranother UL SPS.

When a proposed method is applied, since the base station knows UL SPSshaving the same HPID, the base station may solve the problem ofcollision of the HPIDs of the UL SPSs by performing dynamic scheduling.

The base station may receive a buffer status report (BSR) from theterminal. Accordingly, the base station may dynamically assign a UL datachannel at an appropriate timing based on the BSR. Since an HPID of thedynamically assigned UL data channel may be configured differently froman HPID of the UL SPS, the problem of collision between the HPIDs of theUL SPSs can be solved.

In a proposed method, the HPID may be regarded as the HPID for the SPSPUSCH transmitted later.

The terminal may not necessarily transmit a UL data channel periodicallyaccording to a UL SPS. Therefore, the problem of the transmissionprocedure according to the DL SPS may occur at a low frequency in thetransmission procedure according to the UL SPS. In particular, when theUL SPS supporting the URLLC is performed, the terminal may expect thebase station to proceed with the TB retransmission procedure quickly.Therefore, when a new SPS PUSCH uses the same HPID, the terminal maydelete the existing soft bits stored in the soft buffer and store newsoft bits in the soft buffer.

In a proposed method, the HPID may be used in the SPS PUSCH having ahigh priority along with the UL-DCI for activating the UL SPS.

In this case, the terminal may map a SPS PUSCH having a low priority toa resource of the next period instead of this period. Therefore, theproblem of collision of HPID can be solved.

In a proposed method, HARQ response bits for a SPS PDSCH set may bederived.

A DL SPS set (e.g., a set including two or more DL SPSs) to support DLURLLC traffic may be activated. The DL URLLC traffic may have a certainperiodicity and jitter. Accordingly, as the DL SPSs are activated, theDL URLLC traffic may be delivered to the terminal through SPS PDSCHs.

FIG. 35A is a conceptual diagram illustrating a first exemplaryembodiment of a method for configuring a DL SPS for supporting DL URLLCtraffic in a communication system, FIG. 35B is a conceptual diagramillustrating a second exemplary embodiment of a method for configuring aDL SPS for supporting DL URLLC traffic in a communication system, andFIG. 35C is a conceptual diagram illustrating a third exemplaryembodiment of a method for configuring a DL SPS for supporting DL URLLCtraffic in a communication system.

Referring to FIGS. 35A to 35C, two DL SPSs (e.g., DL SPS a and DL SPS b)may be activated. In the exemplary embodiment shown in FIG. 35A, DLURLLC traffic may occur before a SPS PDSCH #0. In this case, the basestation may transmit the DL URLLC traffic to the terminal on the SPSPDSCH #0. The terminal may receive the DL URLLC traffic on the SPS PDSCH#0, and transmit an HARQ response for the DL URLLC traffic to the basestation. The terminal may expect not to receive the DL URLLC traffic ona SPS PDSCH #1. Accordingly, the terminal may not perform a monitoringoperation for the SPS PDSCH #1 and may not feedback an HARQ response tothe SPS PDSCH #1.

In the exemplary embodiment shown in FIG. 35B, the DL URLLC traffic mayoccur between the SPS PDSCH #0 and the SPS PDSCH #1. The base stationmay not transmit the DL URLLC traffic on the SPS PDSCH #0. The terminalmay perform a monitoring operation for the SPS PDSCH #0. Since the DLURLLC traffic is not received on the SPS PDSCH #0, the terminal may nottransmit an HARQ response for the DL URLLC traffic to the base station.Alternatively, the terminal may feed back a NACK to the base station.

On the other hand, the base station may transmit the DL URLLC traffic tothe terminal on the SPS PDSCH #1. Although the terminal did not detectthe SPS PDSCH #0, the terminal may expect to detect the SPS PDSCH #1.The terminal may detect a DM-RS resource for the SPS PDSCH #1 in orderto detect the SPS PDSCH #1. When the DM-RS resource for the SPS PDSCH #1is detected, the terminal may determine that the SPS PDSCH #1 isreceived. Accordingly, the terminal may receive the DL URLLC traffic onthe SPS PDSCH #1 and transmit an HARQ response for the DL URLLC trafficto the base station.

In the exemplary embodiment shown in FIG. 35C, the DL URLLC traffic mayoccur after the SPS PDSCHs #0 and #1. In this case, the base station mayassign a DL data channel in a dynamic scheduling scheme and transmit theDL URLLC traffic on the DL data channel. The terminal may detect theDM-RS resource of the SPS PDSCH #0, and may determine that the SPS PDSCH#0 is not transmitted when the DM-RS resource is not detected.Therefore, the terminal may not transmit the HARQ response for the SPSPDSCH #0. Alternatively, the terminal may transmit a NACK for the SPSPDSCH #0 to the base station.

In addition, the terminal may detect the DM-RS resource of the SPS PDSCH#1, and may determine that the SPS PDSCH #1 is not transmitted when theDM-RS resource is not detected. Therefore, the terminal may not transmitthe HARQ response for the SPS PDSCH #1. Alternatively, the terminal maytransmit a NACK for the SPS PDSCH #1 to the base station.

In a proposed method, the terminal may not derive an HARQ response bitfor the deactivated SPS PDSCH.

In the conventional method, when the size of the HARQ response codebookis semi-static, the terminal may multiplex HARQ responses for all DLdata channel candidates configured by higher layer signaling. Thisoperation may be performed when one DL SPS is configured in thecommunication system supporting the eMBB service.

In the communication system supporting the URLLC service, the basestation may configure a plurality of DL SPSs in a DL BWP using higherlayer signaling, and may use a DCI to activate one or more DL SPSs amongthe plurality of DL SPSs configured by higher layer signaling. Theterminal may receive DL data through the activated SPS PDSCH(s). Theterminal may not feed back an HARQ response for some SPS PDSCHs amongthe activated SPS PDSCHs. That is, it may be prevented that many HARQresponses are fed back.

In a proposed method, the terminal may feed back HARQ responses for SPSPDSCHs according to one or more DL SPSs among the activated DL SPSs.

Here, the SPS PDSCHs according to the one or more DL SPSs may be SPSPDSCHs actually transmitted from the base station. For example, tosupport transmission of URLLC traffic with a periodicity of 6 ms, thebase station may activate a DL SPS with a periodicity of 2 ms, and maytransmit the SPS PDSCH in one-thirds of total transmission instancesaccording to the activated DL SPS. Since the terminal does not detectthe presence of the SPS PDSCH in two-thirds of the total transmissioninstances according to the activated DL SPS, the terminal may not feedback an HARQ response for the undetected SPS PDSCH.

When it is determined that a SPS PDSCH is not received, the terminal maynot transmit an HARQ response for the corresponding SPS PDSCH. When theterminal feeds back an HARQ response for the SPS PDSCH on a UL controlchannel, the size of the corresponding HARQ response may be 1 bit or 2bits. When it is determined that a SPS PDSCH is not received, theterminal may not transmit a UL control channel for the corresponding SPSPDSCH.

When an HARQ codebook having a semi-static size is configured and it isdetermined that a SPS PDSCH is not received, the terminal may transmit aNACK as an HARQ response for the corresponding SPS PDSCH. When an HARQbook having a dynamic size is configured, a DAI may be configuredwithout consideration of an SPS PDSCH that is not actually transmittedfrom the base station. When a DL data channel is dynamically assignedusing a DL-DCI in a slot to which the SPS PDSCH is assigned or in asubsequent slot of the slot to which the SPS PDSCH is assigned, thenumber of DL data channels indicated by the DAI included in the DL-DCImay not include the SPS PDSCH.

In a proposed method, the terminal may interpret a unit in which the SPSPDSCH is received as a DL SPS set.

Referring back to FIGS. 35A to 35C, one DL SPS set may include two DLSPSs. The maximum size of the HARQ response bits for the DL SPS set maybe 1 bit. When the SPS PDSCH consists of two codewords, the size of HARQresponse bits for the DL SPS set may be up to 2 bits.

When DL URLLC traffic has a large range of jitter, the DL SPS set mayconsist of a large number of DL SPSs. The maximum size of the HARQresponse bits for the DL SPS set may be 1 bit. When the SPS PDSCHconsists of two codewords, the maximum size of the HARQ response bitsfor the DL SPS set may be 2 bits.

When the HARQ response is generated on a DL SPS set basis, the actualposition of the HARQ response bits in the HARQ response codebook may notbe determined according to the reception timing of a SPS PDSCH. This isbecause the base station may not transmit the SPS PDSCH. Therefore, theHARQ response bits may be mapped according to a reference position inthe HARQ response codebook. For example, the reference position may beconfigured based on symbols of an SPS PDSCH of the first DL SPS or thelast DL SPS belonging to the DL SPS set. When the SPS PDSCHs for all theDL SPSs belonging to the DL SPS set are not received, the terminal maymap a NACK to the HARQ response codebook.

In a proposed method, the terminal may generate the HARQ responsecodebook including HARQ response bits for dynamically assigned DL datachannels, and generate the entire HARQ response codebook byconcatenating the HARQ response bits for the SPS PDSCHs in thecorresponding HARQ response codebook.

When there is no HARQ response for the SPS PDSCH, the size of the entireHARQ response codebook generated by the terminal may be reduced. Thebase station may interpret that the size of the entire HARQ responsecodebook has one of two values. Since the SPS PDSCH is assigned by thebase station, the base station may interpret that the size of the entireHARQ response codebook would have one value in implementation.

In a proposed method, the terminal may not transmit an HARQ response forsome SPS PDSCHs among the SPS PDSCHs activated by the base stationaccording to a slot pattern.

The terminal may transmit an HARQ response for the SPS PDSCH on a PUCCH.In the conventional method, an SPS PDSCH may be transmitted in aperiodically allocated resource, and an HARQ response to the SPS PDSCHmay also be transmitted in a periodically allocated resource. However,the terminal may not periodically transmit a PUCCH (e.g., HARQ response)according to a slot format. For example, the PUCCH may not betransmitted in DL symbols. When FL symbols are changed to UL symbols,the PUCCH may be transmitted through the corresponding UL symbols.

In a proposed method, a transmission timing of the HARQ response may bechanged, and the terminal may transmit the HARQ response on a PUCCHcapable of transmitting the HARQ response. For example, the terminal maynot transmit HARQ responses for two SPS PDSCHs in a periodicallyassigned PUCCH. The terminal may multiplex the HARQ responses for thetwo SPS PDSCHs and the HARQ response for the last SPS PDSCH, andtransmit the multiplexed HARQ responses on a PUCCH for the last SPSPDSCH. Therefore, the HARQ response bits transmitted by the terminal mayvary depending on a slot format.

If the terminal does not receive a slot format indicator (SFI) that isdynamically transmitted from the base station, the number of HARQresponse bits may vary. It may be preferable that a transmission timingof the PUCCH for the SPS PDSCH configured to support URLLC traffictransmission is not changed.

In a proposed method, the terminal may not perform a decoding operationfor the corresponding SPS PDSCH when the terminal cannot transmit thePUCCH for the SPS PDSCH. Accordingly, the base station may omittransmission of the corresponding SPS PDSCH (e.g., the SPS PDSCH notdecoded by the terminal). In order to support the transmission of URLLCtraffic in the communication system supporting the TDD scheme, when theterminal determines that PUCCH transmission is impossible according tothe slot format, the base station may assign a PDSCH by the dynamicscheduling scheme instead of the DL SPS.

The exemplary embodiments of the present disclosure may be implementedas program instructions executable by a variety of computers andrecorded on a computer readable medium. The computer readable medium mayinclude a program instruction, a data file, a data structure, or acombination thereof. The program instructions recorded on the computerreadable medium may be designed and configured specifically for thepresent disclosure or can be publicly known and available to those whoare skilled in the field of computer software.

Examples of the computer readable medium may include a hardware devicesuch as ROM, RAM, and flash memory, which are specifically configured tostore and execute the program instructions. Examples of the programinstructions include machine codes made by, for example, a compiler, aswell as high-level language codes executable by a computer, using aninterpreter. The above exemplary hardware device can be configured tooperate as at least one software module in order to perform theembodiments of the present disclosure, and vice versa.

While the exemplary embodiments of the present disclosure and theiradvantages have been described in detail, it should be understood thatvarious changes, substitutions and alterations may be made hereinwithout departing from the scope of the present disclosure.

What is claimed is:
 1. An operation method of a terminal in acommunication system, the operation method comprising: receiving a firstdownlink control information (DCI) in a first control resource set(CORESET); receiving a second DCI in a second CORESET; receiving a thirdDCI in the second CORESET; receiving first data in a first physicaldownlink shared channel (PDSCH) indicated by the first DCI; receivingsecond data in a second PDSCH indicated by the second DCI; receivingthird data in a third PDSCH indicated by the third DCI; generating afirst hybrid automatic repeat request (HARQ) codebook for the firstCORESET based on the first data; generating a second HARQ codebook forthe second CORESET based on the second data and the third data, thesecond HARQ codebook including a second HARQ response bit of the seconddata and a third HARQ response bit of the third data; generating HARQresponse bits by performing a concatenate operation of the first HARQcodebook and the second HARQ codebook; and transmitting the HARQresponse bits in an uplink channel.
 2. The operation method according toclaim 1, wherein the concatenate operation is performed in order of thefirst CORESET and the second CORESET.
 3. The operation method accordingto claim 1, wherein the uplink channel is a physical uplink controlchannel (PUCCH) or a physical uplink shared channel (PUSCH).
 4. Theoperation method according to claim 1, wherein the second HARQ responsebit and the third HARQ response bit are concatenated in order of thesecond DCI and the third DCI in the second HARQ codebook.
 5. Theoperation method of according to claim 4, wherein the order of thesecond DCI and the third DCI is identical to order of a second timedomain resource assignment (TDRA) included in the second DCI and a thirdTDRA included in the third DCI.